I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). Since several years ago, I have been having a problem
running its engine without any choke. It will run if I put it on Full
Choke or at more than 60% choke. But the engine will stop if I reduce
the choke to less than 60%. I was under the impression that this
problem means that the carburetor needs to be fully cleaned. Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. And I also replace some parts
with parts from a repair kit. But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. I notice these:

1. When the engine is running at Full Choke, the throttle valve is
open. I think this is normal because I am running the engine in full
throttle.

2. When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. The engine "seems" to be running fine. But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? What's sucking the throttle valve from Full to Slow?

3. When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... This
opening and closing cycle is like just 1.5 seconds. This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). I don't think
this is normal. But I don't know what is causing it to automatically
closed and then opened again.

4. When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

On Dec 14, 3:21*pm, Jay Chan wrote:
I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

It sounds like you left gas in the tank last season and it cruded up
your carb. Applying the choke increases the vacuum pulling the gas
through your carb so it makes it run even though you cruded up your
carb. Get your carb cleaned. Then use Stabil in your gas from now on.

Jimmie

On Dec 14, 2:39*pm, JIMMIE wrote:
On Dec 14, 3:21*pm, Jay Chan wrote:



I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

It sounds like you left gas in the tank last season and it cruded up
your carb. Applying the choke increases the vacuum pulling the gas
through your carb so it makes it run even though you cruded up your
carb. Get your carb cleaned. Then use Stabil in your gas from now on.

Jimmie

Good advice. One reason why an engine won't run without a choke is
because of an air leak in the intake somewhere and the extra fuel is
needed to make it run.. Make sure all your fuel system gaskets are in
top shape. Good luck.

Joe

Jay Chan wrote:
I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). Since several years ago, I have been having a problem
running its engine without any choke. It will run if I put it on Full
Choke or at more than 60% choke. But the engine will stop if I reduce
the choke to less than 60%. I was under the impression that this
problem means that the carburetor needs to be fully cleaned. Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. And I also replace some parts
with parts from a repair kit. But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. I notice these:

1. When the engine is running at Full Choke, the throttle valve is
open. I think this is normal because I am running the engine in full
throttle.

2. When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. The engine "seems" to be running fine. But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? What's sucking the throttle valve from Full to Slow?

3. When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... This
opening and closing cycle is like just 1.5 seconds. This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). I don't think
this is normal. But I don't know what is causing it to automatically
closed and then opened again.

4. When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

It's either too much air or too little gas. If it's too little gas from
varnish or corrosion in a passage, maybe cleaning didn't remove it.
I've had good luck with Sea Foam. I don't understand why it works. It
seems to be mineral oil, rubbing alcohol, and a little ether, and you
add just a little to your gas.

I think the problem isn't that. I think it's too much air. If it's too
much air, you will need less choke when the engine is under a load
(actually throwing snow). I'd look for a place air might leak in, on
the carburetor or between the carburetor and the intake valve. Loose
fastener? Bad gasket? Disconnected tube?

I had a tachometer that you could clip around the spark-plug cable to
pick up pulses. If your magneto sparks every revolution, you'll get a
reading that's twice as high as the RPMs. I had another tachometer that
was a strobe light. You'd make a mark on a rotating part, start the
engine, turn the strobe down slow, and speed up the strobe until the
mark appeared to freeze.

Jay Chan wrote:

One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?


Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. Keeping the RPMs up can mean better
lubrication and cooling.

On Dec 14, 2:21*pm, Jay Chan wrote:
I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

If by cleaning you mean with spray carb cleaner, that isnt the same as
what you soak them in. Are there needle adjustments on the carb, often
that is all that is needed. 3600 rpm is a base for most all small
power equipment like this, a cheap hour meter usualy has a tach, they
have a wire that wraps around the plug wire

On Dec 14, 4:05*pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. *Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. *Keeping the RPMs up can mean better
lubrication and cooling.

It also sounds like the throttle spring is crazy in its operation.
The throttle spring should keep the throttle closed and the control
should work against the spring to open the throttle. That seems to
not be what the original poster described. ALso If the carburetor
has really beeen cleaned , then an air leak beteen the curburetor body
and the manifold or the manifold and the main engine block is suspect.

Bob Hofmann

hr(bob) wrote:
On Dec 14, 4:05 pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?
Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. Keeping the RPMs up can mean better
lubrication and cooling.

It also sounds like the throttle spring is crazy in its operation.
The throttle spring should keep the throttle closed and the control
should work against the spring to open the throttle. That seems to
not be what the original poster described. ALso If the carburetor
has really beeen cleaned , then an air leak beteen the curburetor body
and the manifold or the manifold and the main engine block is suspect.

Bob Hofmann

The opening and closing at 60% choke makes me think the problem is an
air leak. With 80% choke it gets a good no-load mixture. With 60%,
it's too lean, so the engine slows and the governor opens the throttle.
With the throttle open much wider, the air leak matters much less.
The mixture is better, the engine speeds up, and the governor closes the
throttle. Then it's too lean. Vicious cycle.

Jay Chan wrote:
I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). Since several years ago, I have been having a problem
running its engine without any choke. It will run if I put it on Full
Choke or at more than 60% choke. But the engine will stop if I reduce
the choke to less than 60%. I was under the impression that this
problem means that the carburetor needs to be fully cleaned. Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. And I also replace some parts
with parts from a repair kit. But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. I notice these:

1. When the engine is running at Full Choke, the throttle valve is
open. I think this is normal because I am running the engine in full
throttle.

2. When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. The engine "seems" to be running fine. But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? What's sucking the throttle valve from Full to Slow?

3. When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... This
opening and closing cycle is like just 1.5 seconds. This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). I don't think
this is normal. But I don't know what is causing it to automatically
closed and then opened again.

4. When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan


Usually the banjo bolt that holds the float bowl on clogs, it has some
tiny holes around it near the head that you can clean out with some
piano wire or something similar. As for the tach, the RPM isn't very
critical and you can do it by ear usually, otherwise a stroboscope can
be used to measure it.

Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. Keeping the RPMs up can mean better
lubrication and cooling.

It's more expensive to add the required throttle linkage and most people
never use that feature anyway. More often than not, it comes down to
nothing more than cost of goods to manufacture, though that isn't as
exciting as conspiracy theories.

On Dec 14, 4:05*pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. *Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. *Keeping the RPMs up can mean better
lubrication and cooling.

Slower running engines last longer and run cooler, single speed is
cheap to make. 3600 rpm is normal full speed, cut it in half and motor
life increases at least 4x. Long life engines run very slow.

ransley wrote:
On Dec 14, 4:05 pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?
Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. Keeping the RPMs up can mean better
lubrication and cooling.

Slower running engines last longer and run cooler, single speed is
cheap to make. 3600 rpm is normal full speed, cut it in half and motor
life increases at least 4x. Long life engines run very slow.


And require greater displacement to produce a given horsepower. Like I
said, it all comes down to cost. People want cheap, and they want enough
power to cut their grass. These motors hardly ever wear out before the
equipment they power anyway, change the oil yearly which hardly anyone
ever does and a lawnmower engine can last 50 years.

James Sweet wrote:
ransley wrote:
On Dec 14, 4:05 pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?
Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. Keeping the RPMs up can mean better
lubrication and cooling.

Slower running engines last longer and run cooler, single speed is
cheap to make. 3600 rpm is normal full speed, cut it in half and motor
life increases at least 4x. Long life engines run very slow.


And require greater displacement to produce a given horsepower. Like I
said, it all comes down to cost. People want cheap, and they want enough
power to cut their grass. These motors hardly ever wear out before the
equipment they power anyway, change the oil yearly which hardly anyone
ever does and a lawnmower engine can last 50 years.

My John Deere LA100 manual says idling or operating at less than full
throttle can be harmful. Half throttle should be used only for a warm
start or a brief warm-up after a cold start. Full throttle should be
used for cold starting, running, and shutting off.

I suppose it has a throttle lever for safety, as a quick way to reduce
speed.

On Dec 14, 6:33*pm, James Sweet wrote:
ransley wrote:
On Dec 14, 4:05 pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?
Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. *Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. *Keeping the RPMs up can mean better
lubrication and cooling.

Slower running engines last longer and run cooler, single speed is
cheap to make. 3600 rpm is normal full speed, cut it in half and motor
life increases at least 4x. Long life engines run very slow.

And require greater displacement to produce a given horsepower. Like I
said, it all comes down to cost. People want cheap, and they want enough
power to cut their grass. These motors hardly ever wear out before the
equipment they power anyway, change the oil yearly which hardly anyone
ever does and a lawnmower engine can last 50 years.- Hide quoted text -

- Show quoted text -

An hour rating is better and its from maybe 350-2000 for a cheap
Honda, ive worn out a B&S that was well maintained in 350, and I have
an 83 Lawnboy thats great. 50 years, with a small lawn.

ransley wrote:
On Dec 14, 6:33 pm, James Sweet wrote:
ransley wrote:
On Dec 14, 4:05 pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. I am under the impression that we don't want the
engine to spin too fast and burn itself. That's why we want to keep
its rpm to not more than a certain limit. This means I need a
tachometer. But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? Can we
measure the rpm by timing the number of sparks that the spark plug
makes?
Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. Now my mower has only one speed.
I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. Keeping the RPMs up can mean better
lubrication and cooling.
Slower running engines last longer and run cooler, single speed is
cheap to make. 3600 rpm is normal full speed, cut it in half and motor
life increases at least 4x. Long life engines run very slow.
And require greater displacement to produce a given horsepower. Like I
said, it all comes down to cost. People want cheap, and they want enough
power to cut their grass. These motors hardly ever wear out before the
equipment they power anyway, change the oil yearly which hardly anyone
ever does and a lawnmower engine can last 50 years.- Hide quoted text -

- Show quoted text -

An hour rating is better and its from maybe 350-2000 for a cheap
Honda, ive worn out a B&S that was well maintained in 350, and I have
an 83 Lawnboy thats great. 50 years, with a small lawn.


Yeah that sounds reasonable.

I figure most people mow their lawns about 15 times a year, although
obviously that depends on location. If a typical suburban lawn takes
roughly a half hour to mow, and 350 hours engine life is good for 46
years. Not saying nobody ever wears them out, but I've scrapped a number
of lawnmowers due to rusted out decks but the only motors I've ever
junked were ones somebody ran out of oil.

Joe wrote:
....
... One reason why an engine won't run without a choke is
because of an air leak in the intake somewhere and the extra fuel is
needed to make it run.. Make sure all your fuel system gaskets are in
top shape. ...

Another prime place on many of the Tecumseh engines is around the
throttle axle--they tend to wear out oversize holes in the carb body.
Unfortunately, if that's the problem there's no way to fix permanently
other than replace.

--

On Dec 14, 3:21*pm, Jay Chan wrote:
What is going on here?

You are seeing the engine's GOVERNOR in action. The governor senses
load on the engine, and opens and closes the throttle to maintain a
constant RPM.

When the RPM goes up, the governor closes the throttle.
When the RPM goes down, the governor opens the throttle.

It will run at "full speed" with the throttle 80% closed if you are
not blowing snow. When you start pushing through a snow bank, the
throttle opens up to wide open.

Is the carburetor needed to be cleaned one more time?

Probably. Some things need to be cleaned again, and it needs to be
reassembled correctly. From the sounds of it, the engine is not
getting enough fuel. That's why you have to choke it. Choke reduces
the amount of air coming in and brings the air/fuel mixture back into
balance.

Pay specific attention to the float, needle valve, and seat.

On Dec 14, 6:26*pm, E Z Peaces wrote:
hr(bob) wrote:
On Dec 14, 4:05 pm, E Z Peaces wrote:
Jay Chan wrote:
One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?
Where grass wasn't heavy, I used to throttle my mower down to reduce
noise an save gas. *Now my mower has only one speed.

I think manufacturers have found that engines that can't be run slow
have fewer warranty claims. *Keeping the RPMs up can mean better
lubrication and cooling.

It also sounds like the throttle spring is crazy in its operation.
The throttle spring should keep the throttle closed and the control
should work against the spring to open the throttle. *That seems to
not be what the original poster described. *ALso *If the carburetor
has really beeen cleaned , then an air leak beteen the curburetor body
and the manifold or the manifold and the main engine block is suspect.

Bob Hofmann

The opening and closing at 60% choke makes me think the problem is an
air leak. *With 80% choke it gets a good no-load mixture. *With 60%,
it's too lean, so the engine slows and the governor opens the throttle.
* With the throttle open much wider, the air leak matters much less.
The mixture is better, the engine speeds up, and the governor closes the
throttle. *Then it's too lean. *Vicious cycle.- Hide quoted text -

- Show quoted text -

I think you are probably right.

I disassembled and cleaned the carburetor for the second time. This
time I soaked the main part of the carburetor (the one that has many
holes in it) in carburetor cleaner overnight, and then I used
compressed air to blow all the holes in the carburetor (especically
the holes where the "high speed mixing needle" is, and I observed that
the compressed air could force the carburetor cleaning solution
through the holes. It is all clean. But, the engine still exhibits
the exact same problem. I have a feeling that this problem has
nothing to do with the carburetor being dirty or not. Actually the
carburetor was not that dirty to begin with even before the first
cleaning. It is no where near as bad as those dirty carburetors shown
in YouTube.

I begin to feel that your "air leak" suggestion is probably right
because you seem to be able to explain why the throttle valve behaves
like what it does now.

Although cleaning the carburetor doesn't seem to help, I think I have
found a way to workaround the problem. I turn the "high speed mixing
needle" half a turn more open than what the manufacturer suggested,
and then I find that I can keep the choke at full open, and the engine
doesn't stop, and the throttle valve doesn't exhibit the opening and
closing cycle. Therefore, "may" be the problem was as simple as a mis-
adjusted mixing needle. But I am not sure for the following reason:

When the engine speed lever is at full throttle, and the choke is wide
open, and the engine is not under load, I see that the throttle valve
is almost fully closed. I don't know how the engine is getting air
under this situation because the throttle valve plate doesn't have any
hole in it. The air must be coming from some where. I thought the
engine might not need that much air when it was not under load. But
when I put the engine under load, I see that the engine speed up and
the throttle valve briefly open. But the engine "sounds" like it
quickly slows back down and the throttle valve goes back to almost
fully closed.

My questions a

1. Where does the engine get air when it is under load and the
throttle valve is somehow closed? Is there a big air leak somewhere?

2. Where is the likely air leak? There is no gasket between the
engine air intake and the carburetor. I don't see a gasket there, and
the Technical Manual doesn't show there is a gasket either. May be I
should try adding some gasket in a tube kind of thing? Other than
this, where else is the likely air leak? Does this mean that I need
to fully disassemble the whole engine block?

3. The fact is that I can keep the choke at full open after I have
adjusted the mixing needle. Does this mean that I have no problem
getting fuel from the mixing needle? Does this also mean that dirty
carburetor is not an issue here?

4. What is the problem of running this snow thrower as is? I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? Sorry, I don't have any snow on the ground to test this.

By the way, can you show me a link to the tachometer that you use to
connect to the spark plug? May be I am not using the correct key
words to search for it because I cannot find it in the net.

Jay Chan

On Dec 15, 1:24*pm, wrote:
On Dec 14, 3:21*pm, Jay Chan wrote:

What is going on here?

You are seeing the engine's GOVERNOR in action. The governor senses
load on the engine, and opens and closes the throttle to maintain a
constant RPM.

When the RPM goes up, the governor closes the throttle.
When the RPM goes down, the governor opens the throttle.

It will run at "full speed" with the throttle 80% closed if you are
not blowing snow. When you start pushing through a snow bank, the
throttle opens up to wide open.

Is the carburetor needed to be cleaned one more time?

Probably. Some things need to be cleaned again, and it needs to be
reassembled correctly. From the sounds of it, the engine is not
getting enough fuel. That's why you have to choke it. Choke reduces
the amount of air coming in and brings the air/fuel mixture back into
balance.

Pay specific attention to the float, needle valve, and seat.

Thanks for the suggestion. You are right about the engine is not
getting enough fuel and the mixing needle needs to be adjusted. As
mentioned in my other post, after I have turned the mixing needle an
additional 1/2 turn more open than what the manufacturer suggested, I
can keep the choke fully opened and the engine will not stop. Seem
like this is the way to send enough fuel to the engine. Still, as
mentioned in my other post, the throttle valve is somehow closed even
though the engine is under load and the speed lever is set at high
speed.

Jay Chan

Jay Chan wrote:


My questions a

1. Where does the engine get air when it is under load and the
throttle valve is somehow closed? Is there a big air leak somewhere?

If there's no snow, I guess you aren't running it under a load. It
shouldn't take much throttle to run the engine pretty fast without a
load. If there's an air leak, it would take even less throttle opening.

2. Where is the likely air leak? There is no gasket between the
engine air intake and the carburetor. I don't see a gasket there, and
the Technical Manual doesn't show there is a gasket either. May be I
should try adding some gasket in a tube kind of thing? Other than
this, where else is the likely air leak? Does this mean that I need
to fully disassemble the whole engine block?

I can't remember if air can be sucked in past a cylinder-head gasket.
Why not take a syringe and squirt water around the carburetor and
cylinder head? If you can affect the engine speed that way, you've
found an air leak.

3. The fact is that I can keep the choke at full open after I have
adjusted the mixing needle. Does this mean that I have no problem
getting fuel from the mixing needle? Does this also mean that dirty
carburetor is not an issue here?

There could be a passage to add a little gas at low throttle settings.
That part could be clogged. (I don't know if your carburetor has such a
passage.)

4. What is the problem of running this snow thrower as is? I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? Sorry, I don't have any snow on the ground to test this.

If it's an air leak, the engine may run rich when the throttle stays
open to throw snow. With the throttle open, the air leak would matter
less and the rich adjustment of the mixing needle would matter more.

By the way, can you show me a link to the tachometer that you use to
connect to the spark plug? May be I am not using the correct key
words to search for it because I cannot find it in the net.

I may have found something better, a vibra tach. You put it against the
engine and adjust it so the reed vibrates the most.

On Dec 16, 6:12*pm, E Z Peaces wrote:
Jay Chan wrote:

My questions a

1. * Where does the engine get air when it is under load and the
throttle valve is somehow closed? *Is there a big air leak somewhere?

If there's no snow, I guess you aren't running it under a load. *It
shouldn't take much throttle to run the engine pretty fast without a
load. *If there's an air leak, it would take even less throttle opening..


Thanks for the reply.

I try running the snow thrower under load by the combination of using
the self-propel function of the snow throw to run it in high speed,
and using the snow throwing mechanism at the same time. But the
throttle valve is still closed when I run it under load. There is a V-
belt connecting the engine to the snow throwing mechanism. If I turn
off the snow throwing mechanism, the V-belt will dis-engage the engine
from the snow throwing mechanism, and put the engine off the load. On
the other hand, if I turn ON the snow throwing mechanism, the V-belt
will engage the engine with the snow throwing mechanism, and I believe
this puts the engine under load.


2. * Where is the likely air leak? *There is no gasket between the
engine air intake and the carburetor. *I don't see a gasket there, and
the Technical Manual doesn't show there is a gasket either. *May be I
should try adding some gasket in a tube kind of thing? *Other than
this, where else is the likely air leak? *Does this mean that I need
to fully disassemble the whole engine block?

I can't remember if air can be sucked in past a cylinder-head gasket.
Why not take a syringe and squirt water around the carburetor and
cylinder head? *If you can affect the engine speed that way, you've
found an air leak.


Test didn't reveal where the air leak is. I tested this by using both
a feather and the water test. I tested this around the engine,
especially in the joint of the carburetor and the engine cylinder.
The feather didn't show any air movement when the engine was running
-- except near the fly wheel where I believe the cooling fan is.. And
the water test didn't slow the engine in anyway. Therefore, I don't
know where the air leak is.


3. * The fact is that I can keep the choke at full open after I have
adjusted the mixing needle. *Does this mean that I have no problem
getting fuel from the mixing needle? *Does this also mean that dirty
carburetor is not an issue here?

There could be a passage to add a little gas at low throttle settings.
That part could be clogged. *(I don't know if your carburetor has such a
passage.)


There is an "Idle Mixing Needle" and the channel for it. And I have
cleaned it and used compressed air to blow the channel. Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.


4. * What is the problem of running this snow thrower as is? *I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. *Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? *Sorry, I don't have any snow on the ground to test this.

If it's an air leak, the engine may run rich when the throttle stays
open to throw snow. *With the throttle open, the air leak would matter
less and the rich adjustment of the mixing needle would matter more.


If there is an air leak and the throttle stays open under load, the
engine should be running lean because of the extra air. This may
explain the reason why the "engine-stall" problem goes away when I
open up the high speed mixing needle an additional 1/2 turn to add
extra fuel to the carburetor. Is this what you are trying to tell me?

By the way, can you show me a link to the tachometer that you use to
connect to the spark plug? *May be I am not using the correct key
words to search for it because I cannot find it in the net.

I may have found something better, a vibra tach. *You put it against the
engine and adjust it so the reed vibrates the most.

I think I have found what it is called. It is called "Hour Timer" and
is connected to a spark plug to count the number of sparks. I have
decided to get an optical tachnmeter instead. The reason is that it
is cheap, and I have found a way to get access to the spinning part of
the engine.

Seem like I cannot determine where the air leak is, and I am not sure
if the engine really has an air leak or not. Therefore, I need to get
a tachometer to see if the engine can run in high speed or not. If
the engine can run in high speed, this may mean I really don't have a
problem, and I may just have to accept the fact that the throttle
valve cannot open wide. If the tachometer shows that the engine
cannot run in high speed when it is supposed to be, this means I
really have a problem, and I will try to manually open the throttle
valve slowly to see if doing this can make the engine run in the
correct high speed (3600 rpm). If the engine can run in the proper
high speed when I manually open the throttle valve, this may mean that
the spring that is supposed to keep the throttle valve open has become
too weak, and the suction from the engine is too powerful for the weak
spring and sucks the throttle valve closed. That's despite the fact
that the spring "seemed" strong when I manually moved it around.

Because I need to manually open the throttle valve, I am afraid that I
may run the engine too fast. Therefore, I definitely need to get a
tachometer before I do anything further.

Jay Chan

On Dec 14, 5:12*pm, ransley wrote:
On Dec 14, 2:21*pm, Jay Chan wrote:





I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

If by cleaning you mean with spray carb cleaner, that isnt the same as
what you soak them in. Are there needle adjustments on the carb, often
that is all that is needed. 3600 rpm is a base for most all small
power equipment like this, a cheap hour meter usualy has a tach, they
have a wire that wraps around the plug wire- Hide quoted text -

- Show quoted text -

Thanks for telling me that the type of tachometer is called "Hour
Meter".

Having said this I decide to get a cheap optical tachometer. The
reason is that I have found a way to get access to the spinning part
of the engine, and I can use the optical tachometer to measure the rpm
of the spinning part of the engine.

Jay Chan

On Dec 16, 8:43*pm, Jay Chan wrote:
On Dec 14, 5:12*pm, ransley wrote:





On Dec 14, 2:21*pm, Jay Chan wrote:

I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

If by cleaning you mean with spray carb cleaner, that isnt the same as
what you soak them in. Are there needle adjustments on the carb, often
that is all that is needed. 3600 rpm is a base for most all small
power equipment like this, a cheap hour meter usualy has a tach, they
have a wire that wraps around the plug wire- Hide quoted text -

- Show quoted text -

Thanks for telling me that the type of tachometer is called "Hour
Meter".

Having said this I decide to get a cheap optical tachometer. *The
reason is that I have found a way to get access to the spinning part
of the engine, and I can use the optical tachometer to measure the rpm
of the spinning part of the engine.

Jay Chan- Hide quoted text -

- Show quoted text -

Jay,

the throttle on these small engines is controlled by a GOVERNOR
system, when the engine is under light load, the throttle will be
more closed, when the engine is under heavy load the governor senses
the engine trying to slow down and will open the throttle to tey to
keep it running at a constant speed as the load changes. The governor
usually is a mechanical setup with springs and rotating weightsw or
fan air pressure usually inside the engine that you cannot see. All
you see of the governor is a lever that comes out of the engine and is
connected to the springs. This level is suposed to move as a fnuction
of the engine spped. You have to understand the concept of the
governor to troubleshoot these problems. If you disable the goverenor
and operate the engine at wide open throttle and no load, IT WILL over
rev and can possible fly apart, that can be dangerous. If you don't
nuderstand all this., proceed with caution. When you first start it
up after any repair, you have to be ready to SHUT ER DOWN immediatly
if it starts to over rev. There are many good websites on small
engine repair.

Mark

On Dec 16, 9:10*pm, wrote:
On Dec 16, 8:43*pm, Jay Chan wrote:





On Dec 14, 5:12*pm, ransley wrote:

On Dec 14, 2:21*pm, Jay Chan wrote:

I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.
What is so powerful that it can suck/push this throttle valve to
close?

Is the carburetor needed to be cleaned one more time?

One additional question: *The Tech Manual from John Deere asks me to
make sure the engine is running at 3600 rpm when the engine is set at
high-speed mode. *I am under the impression that we don't want the
engine to spin too fast and burn itself. *That's why we want to keep
its rpm to not more than a certain limit. *This means I need a
tachometer. *But tachometer seems to require seeing or touching the
spinning part of the tachometer in order to measure the rpm.
Unfortunately the engine is fully enclosed, and I cannot see the
spinning part of the engine. *Is there any tachometer that doesn't
require seeing or touching the spinning part of the engine? *Can we
measure the rpm by timing the number of sparks that the spark plug
makes?

Thanks in advance for any help.

Jay Chan

If by cleaning you mean with spray carb cleaner, that isnt the same as
what you soak them in. Are there needle adjustments on the carb, often
that is all that is needed. 3600 rpm is a base for most all small
power equipment like this, a cheap hour meter usualy has a tach, they
have a wire that wraps around the plug wire- Hide quoted text -

- Show quoted text -

Thanks for telling me that the type of tachometer is called "Hour
Meter".

Having said this I decide to get a cheap optical tachometer. *The
reason is that I have found a way to get access to the spinning part
of the engine, and I can use the optical tachometer to measure the rpm
of the spinning part of the engine.

Jay Chan- Hide quoted text -

- Show quoted text -

Jay,

the throttle on these small engines is controlled by a GOVERNOR
system, *when the engine is under light load, the throttle will be
more closed, when the engine is under heavy load the governor senses
the engine trying to slow down and will open the throttle to tey to
keep it running at a constant speed as the load changes. The governor
usually *is a mechanical setup with springs and rotating weightsw or
fan air pressure usually inside the engine that you cannot see. *All
you see of the governor is a lever that comes out of the engine and is
connected to the springs. *This level is suposed to move as a fnuction
of the engine spped. * You have to understand the concept of the
governor to troubleshoot these problems. *If you disable the goverenor
and operate the engine at wide open throttle and no load, IT WILL over
rev and can possible fly apart, that can be dangerous. * If you don't
nuderstand all this., proceed with caution. *When you first start it
up after any repair, you have to be ready to SHUT ER DOWN immediatly
if it starts to over rev. * There are many good websites on small
engine repair.

Mark- Hide quoted text -

- Show quoted text -

Thanks for taking the time to warn me about the danger of letting the
engine to spin too fast. Yes, I know about this. This is the reason
why I want to get a tachometer to make sure I don't let the engine to
spin more than what the manufacturer's has recommended (3600 rpm). So
far, just by hearing the sound from the engine, the problem with the
engine seems to be running too slow and is not running too fast. The
tachometer will arrive in this weekend or early next week just in time
as a X'mas gift for myself.

Currently I am suspecting that the spring that is supposed to keep the
throttle valve open may have become weak; I am waiting for the
tachometer before testing this theory in case I manually open the
throttle valve too wide and let the engine spins too fast. Or the
throttle lever arm is not setup in the correct position; I checked
this once by following the manufacturer's recommended setup and I
don't think this is the problem.

The hardest part that I can think of is how to simulate the situation
when it is running under load while monitoring the rpm using a
tachometer. Currently there is no snow on the ground to test the snow
thrower. Even if there was snow on the ground, I would have a hard
time using the machine to throw snow while holding the handheld
tachometer to point at the spinning part of the engine. I may just
have to lift the wheels off the ground with wood blocks, and let the
wheels and the snow throwing mechanism to free spin. Seem like a
"Hour Meter" is a better device for this test instead of the handheld
tachometer that I have ordered. Oh well...

Jay Chan

Jay Chan wrote:


There is an "Idle Mixing Needle" and the channel for it. And I have
cleaned it and used compressed air to blow the channel. Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.

There's an idle mixing needle! Great! That should help troubleshooting.

When carburetor people talk about idle and high speed, they're really
talking about throttle opening. You say the throttle is pretty well
closed, so the idle mixing needle should be the most important adjustment.

1. Does turning the needle affect engine speed? If not, it sounds as
if a channel is clogged.

2. Can you turn the high-speed needle to where the manual suggests,
then adjust the idle mixing needle to run the engine with no choke? If
you can, and that adjustment is reasonably close to what the manual
suggests, great! No air leak!



4. What is the problem of running this snow thrower as is? I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? Sorry, I don't have any snow on the ground to test this.
If it's an air leak, the engine may run rich when the throttle stays
open to throw snow. With the throttle open, the air leak would matter
less and the rich adjustment of the mixing needle would matter more.


If there is an air leak and the throttle stays open under load, the
engine should be running lean because of the extra air. This may
explain the reason why the "engine-stall" problem goes away when I
open up the high speed mixing needle an additional 1/2 turn to add
extra fuel to the carburetor. Is this what you are trying to tell me?

Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. That will make the mixture leaner. If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets, so
it won't matter much.

On Dec 17, 2:39*pm, E Z Peaces wrote:
Jay Chan wrote:

There is an "Idle Mixing Needle" and the channel for it. *And I have
cleaned it and used compressed air to blow the channel. *Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.

There's an idle mixing needle! *Great! *That should help troubleshooting.

When carburetor people talk about idle and high speed, they're really
talking about throttle opening. *You say the throttle is pretty well
closed, so the idle mixing needle should be the most important adjustment..

1. *Does turning the needle affect engine speed? *If not, it sounds as
if a channel is clogged.

2. *Can you turn the high-speed needle to where the manual suggests,
then adjust the idle mixing needle to run the engine with no choke? *If
you can, and that adjustment is reasonably close to what the manual
suggests, great! *No air leak!


The engine speeds up and slows down following the adjustment of the
idle mixing needle. I guess this means the channel related to the
idle mixing needle is not clogged. But adjusting the idle mixing
needle only has effect if the high speed mixing needle has opened 1/2
turn more than the manufacturer's suggested initial setting.
Otherwise, adjusting the idle mixing needle doesn't have any effect.

I have also tried setting the high speed mixing needle back to the
manufacturer suggested initial setting, and then trying to adjust the
idle mixing needle to see if I can run the engine with no choke. But
this doesn't work. Doesn't matter how I adjust the mixing idle
needle, the engine still needs to have some choke (at least 40 to 50%
choke). Even with 50% choke, the throttle valve is opening and
closing by itself frequently. The only way to make the engine running
without any choke and without having the throttle valve opening and
closing like crazy is to turn the high speed mixing needle 1/2 turn
more open than what the manufacturer has suggested (from 1-1/4 turn to
1-3/4 turn). This is as far as I can manage to achieve; still, the
throttle valve is mostly closed.

Having said this, I have a feeling that this may not be a problem for
three reasons:

1. The manufacturer suggested setting is just a initial setting. The
manufacturer expects us to adjust it. Therefore, the fact that I need
to keep the high speed mixing needle more open than what the
manufacturer has suggested as the initial setting may not mean that
there is anything wrong -- I think.

2. The fact that the throttle valve is mostly closed when the engine
seems to be running OK even under load may not mean much. The load
that I put on the engine is a "simulated" load, not real load. I am
just letting the wheels of the snow thrower and the snow throwing
mechanism free spinning. This "simulated" load may not be enough for
the engine to open the throttle valve. I will have to try this again
with real load when there is snow on the ground.

3. The engine sounds fine when I turn the lever in high speed with no
choke. This may mean that the engine is running at the correct rpm.
Having said this, I don't quite remember how the engine sound is
supposed to be -- afterall, this snow thrower has not run right for
two years. I will have to wait for the tachnmeter to use it to
confirm if the engine is running at the right rpm.

Therefore, I may not really have a problem -- that's after I have
cleaned the carburetor and adjusted the high speed mixing needle.


4. * What is the problem of running this snow thrower as is? *I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. *Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? *Sorry, I don't have any snow on the ground to test this.

If it's an air leak, the engine may run rich when the throttle stays
open to throw snow. *With the throttle open, the air leak would matter
less and the rich adjustment of the mixing needle would matter more.

If there is an air leak and the throttle stays open under load, the
engine should be running lean because of the extra air. *This may
explain the reason why the "engine-stall" problem goes away when I
open up the high speed mixing needle an additional 1/2 turn to add
extra fuel to the carburetor. *Is this what you are trying to tell me?

Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. *That will make the mixture leaner. *If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets, so
it won't matter much.


OK, I understand what you mean. I just don't know how this is related
to my situation.
Thanks anyway.

Jay Chan

On Dec 17, 7:11*pm, Jay Chan wrote:
On Dec 17, 2:39*pm, E Z Peaces wrote:





Jay Chan wrote:

There is an "Idle Mixing Needle" and the channel for it. *And I have
cleaned it and used compressed air to blow the channel. *Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.

There's an idle mixing needle! *Great! *That should help troubleshooting.

When carburetor people talk about idle and high speed, they're really
talking about throttle opening. *You say the throttle is pretty well
closed, so the idle mixing needle should be the most important adjustment.

On Dec 17, 11:19*am, Jay Chan wrote:
On Dec 16, 9:10*pm, wrote:





On Dec 16, 8:43*pm, Jay Chan wrote:

On Dec 14, 5:12*pm, ransley wrote:

On Dec 14, 2:21*pm, Jay Chan wrote:

I have a John Deere Snow Thrower Model 522 that has a Tecumseh engine
(model HSSK50). *Since several years ago, I have been having a problem
running its engine without any choke. *It will run if I put it on Full
Choke or at more than 60% choke. *But the engine will stop if I reduce
the choke to less than 60%. *I was under the impression that this
problem means that the carburetor needs to be fully cleaned. *Today, I
finally have the carburetor fully disassembled and sprayed and soaked
the components in carburetor cleaner. *And I also replace some parts
with parts from a repair kit. *But after I have cleaned it and re-
assembled it, I find that the problem is still there.

Now that I have the carburetor cover removed, I can see the arms of
the various valves of the carburetor in action. *I notice these:

1. *When the engine is running at Full Choke, the throttle valve is
open. *I think this is normal because I am running the engine in full
throttle.

2. *When the engine is running at 80% choke, I notice that the
throttle valve is nearly closed. *This is odd because I have set the
throttle lever to Full (Fast); the throttle valve seems to be closing
by itself. *The engine "seems" to be running fine. *But I have a
feeling that the engine "sounds" like it is running in slow throttle.
Is this normal? *What's sucking the throttle valve from Full to Slow?

3. *When the engine is running at less than 60% choke, I notice that
the throttle valve is opening and closing, opening and closing, and so
on ... all by itself. *Therefore, the engine is speeding up and then
slowing down, speeding up and then slowing down, and so on... * This
opening and closing cycle is like just 1.5 seconds. *This opening and
closing cycle will increase to something like 2 seconds if I slightly
open the choke just a bit (something like 55% choke). *I don't think
this is normal. *But I don't know what is causing it to automatically
closed and then opened again.

4. *When the engine is running at 50% choke or lower (less choke, more
open), the engine will stop, and the throttle valve will go back to
the full open.

What is going on here? *I have checked the spring that keeps the
throttle valve at full open (and is the one linked to the throttle
lever), and it seems strong enough to keep the throttle valve at full
open position if the throttle level is in the Full (Fast) position.

Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. That will make the mixture leaner. If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets, so
it won't matter much.

OK, I understand what you mean. I just don't know how this is related
to my situation.
Thanks anyway.

Jay Chan- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -


Don't forget about the points. They can cause symptoms that one would swear
up and down were carburetor problems. Maybe your problem isn't in the
carburetor at all.

Dan

2. *The fact that the throttle valve is mostly closed when the engine
seems to be running OK even under load may not mean much. * The load
that I put on the engine is a "simulated" load, not real load. *I am
just letting the wheels of the snow thrower and the snow throwing
mechanism free spinning. *This "simulated" load may not be enough for
the engine to open the throttle valve. *I will have to try this again
with real load when there is snow on the ground.


That is correct, what you describe is basically NO LOAD. Just free
turning the wheels and snow screw is NOT a load. It is normal for the
throttle to be mostly closed and the enhine running at 3600rpm in this
condition. Put the machine on the ground and let it pull itself up a
hill... You want the engine to have reserve POWER so that it can
maintain 3600rpm even under a heavy load. That means it is normal for
the throttle to be NOT full open at 3600 RPM except under the most
heavy of loads.

Mark

On Dec 19, 9:11*am, "Dan Kuechle" wrote:
Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. That will make the mixture leaner. If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets, so
it won't matter much.

OK, I understand what you mean. I just don't know how this is related
to my situation.
Thanks anyway.

Jay Chan- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Don't forget about the points. *They can cause symptoms that one would swear
up and down were carburetor problems. *Maybe your problem isn't in the
carburetor at all.

Dan

I don't know what you mean about the "points". Which parts of the
engine are called "points"?

Yes, the problem may not have to do with the carburetor. Now, I am
concentrate on the fact that the engine idles fast (not slow).
According to other web sites, this likely means that there is an air
leak somewhere in the engine.

Jay Chan

On Dec 19, 9:57*am, wrote:
2. *The fact that the throttle valve is mostly closed when the engine
seems to be running OK even under load may not mean much. * The load
that I put on the engine is a "simulated" load, not real load. *I am
just letting the wheels of the snow thrower and the snow throwing
mechanism free spinning. *This "simulated" load may not be enough for
the engine to open the throttle valve. *I will have to try this again
with real load when there is snow on the ground.

That is correct, what you describe is basically NO LOAD. *Just free
turning the wheels and snow screw is NOT a load. *It is normal for the
throttle to be mostly closed and the enhine running at 3600rpm in this
condition. *Put the machine on the ground and let it pull itself up a
hill... You want the engine to have reserve POWER so that it can
maintain 3600rpm even under a heavy load. *That means it is normal for
the throttle to be NOT full open at 3600 RPM except under the most
heavy of loads.

Mark

Thanks for pointing out that "my simulated load" is just like "no
load". As soon as the snow stops, I will try running the machine up
the hill (my driveway) while throwing snow at the same time to put it
under load to see if the throttle valve will open or not. Seem like I
have plenty of opportunity to put the machine (and myself) under load
today.

Also thanks for telling me that this is normal for the throttle valve
to be closed if the engine is not under load (that is even if we have
turned the speed lever to High). I mistakenly assumed that the
throttle valve should open up strictly following the speed lever.
Thanks for the correction.

Jay Chan

On Dec 17, 2:39*pm, E Z Peaces wrote:
Jay Chan wrote:

There is an "Idle Mixing Needle" and the channel for it. *And I have
cleaned it and used compressed air to blow the channel. *Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.

There's an idle mixing needle! *Great! *That should help troubleshooting.

When carburetor people talk about idle and high speed, they're really
talking about throttle opening. *You say the throttle is pretty well
closed, so the idle mixing needle should be the most important adjustment..

1. *Does turning the needle affect engine speed? *If not, it sounds as
if a channel is clogged.

2. *Can you turn the high-speed needle to where the manual suggests,
then adjust the idle mixing needle to run the engine with no choke? *If
you can, and that adjustment is reasonably close to what the manual
suggests, great! *No air leak!







4. * What is the problem of running this snow thrower as is? *I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. *Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? *Sorry, I don't have any snow on the ground to test this.
If it's an air leak, the engine may run rich when the throttle stays
open to throw snow. *With the throttle open, the air leak would matter
less and the rich adjustment of the mixing needle would matter more.

If there is an air leak and the throttle stays open under load, the
engine should be running lean because of the extra air. *This may
explain the reason why the "engine-stall" problem goes away when I
open up the high speed mixing needle an additional 1/2 turn to add
extra fuel to the carburetor. *Is this what you are trying to tell me?

Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. *That will make the mixture leaner. *If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets, so
it won't matter much.- Hide quoted text -

- Show quoted text -

As mentioned in another of my post, I find that the engine cannot idle
slow. According to other web sites, this means there is likely an air
leak somewhere in the engine. Seem like you are right.

The hard part is to find out where the air leak is. And I will need
to connect an air regulator to my small air compressor and inject 3-
lbs-per-sq-in air through the choke air intake and spray soapy water
around the engine to see where the bubbles will come out.

Meanwhile, I will have to start using the snow thrower today and
tomorrow regardless the fact that the engine cannot idle snow. I
think it should not hurt the engine -- just burn more gas.

Jay Chan

On Dec 18, 7:35*pm, Jay Chan wrote:
but the throttle valve somehow is closed

You have had the engine governor explained to you several times now in
this thread. Everything is working properly.

Most likely no points in this engine. Electronic ign.
"Dan Kuechle" wrote in message
om...
Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. That will make the mixture leaner. If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets,
so
it won't matter much.

OK, I understand what you mean. I just don't know how this is related
to my situation.
Thanks anyway.

Jay Chan- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -


Don't forget about the points. They can cause symptoms that one would
swear up and down were carburetor problems. Maybe your problem isn't in
the carburetor at all.

Dan

On Dec 19, 11:42*am, Jay Chan wrote:
On Dec 17, 2:39*pm, E Z Peaces wrote:





Jay Chan wrote:

There is an "Idle Mixing Needle" and the channel for it. *And I have
cleaned it and used compressed air to blow the channel. *Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.

There's an idle mixing needle! *Great! *That should help troubleshooting.

When carburetor people talk about idle and high speed, they're really
talking about throttle opening. *You say the throttle is pretty well
closed, so the idle mixing needle should be the most important adjustment.

Jay Chan wrote:
On Dec 17, 7:11 pm, Jay Chan wrote:


I have received the tachometer. I immediately try it and find that
the engine can run close to the manufacturer's suggested speed (3600
rpm) when I set the speed lever to high speed. But the problem is
that when I set the speed lever to low idle speed, the engine still
run at high speed (3400 rpm instead of 1700 rpm as what the
manufacturer's suggested speed). This means I have a problem.

If it happened to me, I'd dial the tach back to 1700 and see if it
showed just one mark. If it's a strobe, it can read 2x, 3x, or 4x the
actual RPMs.

If it really is idling too fast, maybe you need to adjust the idle-speed
screw. It's a screw the throttle bumps when it closes. All carburetors
used to have them.

Each time you unscrew the idle-speed screw a little, you adjust the idle
mixture needle for the fastest idle. Then unscrew the idle-speed screw
a little more.

On Dec 19, 6:28*pm, ransley wrote:
On Dec 19, 11:42*am, Jay Chan wrote:





On Dec 17, 2:39*pm, E Z Peaces wrote:

Jay Chan wrote:

There is an "Idle Mixing Needle" and the channel for it. *And I have
cleaned it and used compressed air to blow the channel. *Honestly, I
don't know if this matters or not because the problem that I have is
with running the engine in high speed; therefore, the idle mixing
needle should be irrelevant.

There's an idle mixing needle! *Great! *That should help troubleshooting.

When carburetor people talk about idle and high speed, they're really
talking about throttle opening. *You say the throttle is pretty well
closed, so the idle mixing needle should be the most important adjustment.

1. *Does turning the needle affect engine speed? *If not, it sounds as
if a channel is clogged.

2. *Can you turn the high-speed needle to where the manual suggests,
then adjust the idle mixing needle to run the engine with no choke? *If
you can, and that adjustment is reasonably close to what the manual
suggests, great! *No air leak!

4. * What is the problem of running this snow thrower as is? *I mean
running it in full open choke, with the speed lever at high speed, but
the throttle valve is somehow closed. *Does this mean that the snow
thrower will run slow and cannot throw the snow to the proper
distance? *Sorry, I don't have any snow on the ground to test this.
If it's an air leak, the engine may run rich when the throttle stays
open to throw snow. *With the throttle open, the air leak would matter
less and the rich adjustment of the mixing needle would matter more.

If there is an air leak and the throttle stays open under load, the
engine should be running lean because of the extra air. *This may
explain the reason why the "engine-stall" problem goes away when I
open up the high speed mixing needle an additional 1/2 turn to add
extra fuel to the carburetor. *Is this what you are trying to tell me?

Suppose the throttle is closed and the leak adds 10% to the air the
engine gets. *That will make the mixture leaner. *If you open the
throttle to let 10 times more air through the carburetor and the leak
stays the same, it will be adding only 1% to the air the engine gets, so
it won't matter much.- Hide quoted text -

- Show quoted text -

As mentioned in another of my post, I find that the engine cannot idle
slow. *According to other web sites, this means there is likely an air
leak somewhere in the engine. *Seem like you are right.

The hard part is to find out where the air leak is. *And I will need
to connect an air regulator to my small air compressor and inject 3-
lbs-per-sq-in air through the choke air intake and spray soapy water
around the engine to see where the bubbles will come out.

Meanwhile, I will have to start using the snow thrower today and
tomorrow regardless the fact that the engine cannot idle snow. *I
think it should not hurt the engine -- just burn more gas.

Jay Chan- Hide quoted text -

- Show quoted text -

Did it ever idle slow, mine dont.- Hide quoted text -

- Show quoted text -

I received the snow thrower as a "hand me down" years ago. I was not
able to set the speed lever to low. If I tried, the engine would
stop. After I cleaned the carburetor a week ago and made adjustment
on the high speed mixing needle, I can put the speed lever to low and
the engine will continue running. The only remaining problem is that
the engine will run in high rpm, not in slow idle speed.

Based on the research on another web site and what have been suggested
in this news group, the problem might have to do with air leak. The
engine may get air elsewhere from air leak (not just from the air
inlet in the carburetor). I don't fully understand this. But I just
have to keep this in mind.

Because of the fact that I have been using the snow thrower for years
without the use of running it in idle speed, I probably will leave
this problem alone.

Jay Chan

On Dec 19, 11:17*pm, E Z Peaces wrote:
Jay Chan wrote:
On Dec 17, 7:11 pm, Jay Chan wrote:

I have received the tachometer. *I immediately try it and find that
the engine can run close to the manufacturer's suggested speed (3600
rpm) when I set the speed lever to high speed. *But the problem is
that when I set the speed lever to low idle speed, the engine still
run at high speed (3400 rpm instead of 1700 rpm as what the
manufacturer's suggested speed). *This means I have a problem.

If it happened to me, I'd dial the tach back to 1700 and see if it
showed just one mark. *If it's a strobe, it can read 2x, 3x, or 4x the
actual RPMs.

If it really is idling too fast, maybe you need to adjust the idle-speed
screw. *It's a screw the throttle bumps when it closes. *All carburetors
used to have them.

Each time you unscrew the idle-speed screw a little, you adjust the idle
mixture needle for the fastest idle. *Then unscrew the idle-speed screw
a little more.

No, the tachometer doesn't have the option to see the number in 2x,
3x... This tachometer shows the actual rpm of the engine shaft, not
the number of sparks from a spark plug.

I tried adjustng the idle speed mixing needle; but that didn't make a
difference.

In the past weekend, I tested the snow thrower with real load (12" of
snow), and I found that I could not make the throttle valve open more
than just a little. Anyway, the snow thrower was working fine and
could throw snow 20-ft away _if_ the snow was not wet.

At this point, I have decided to live with the minor problem of
"cannot slow to idle speed". I could not run the engine at idle speed
since I received the snow thrower as a "hand me down". I don't have a
need to run the engine in idle speed any way.

After I have cleaned the carburetor and adjusted the high speed mixing
needle, I have found the following good things:

(1) I can run the engine without any choke (that had been bothering
me for two years).

(2) I can pull start the engine with just one pull. I used to always
use electric start because hand pull didn't work before from day one
when I received it.

(3) I can put the speed lever to idle and the engine doesn't stop
(that I could not do from day one) (the engine is still running in
high speed though).

All in all, there are a lot of positive things. Therefore, I am happy
with the outcome. And I consider all these positive things as X'mas
gifts to myself (in addition to a Rockwell SoniCrafter power tool that
I have ordered for myself).

Thanks for everyone who has replied and helped.

Jay Chan