I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

Ned Flanders wrote:
....

I am thinking a gasket...
....
If so, compression will be shot or at least quite low...

--

On Jun 26, 6:22*pm, Ned Flanders wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

If it starts and then dies when the thottle is being opened, that
means it is running a lean mixture. This can be caused by many things
such as a dirty carb, bad gasket between carb and head, loose
headbolts or bad head gasket, valves need adjusting.

Start with tighening everything down. If that don't get it, check
vavlve clearance, then replace manifold gasket. Since you have the
carb off, clean it thoroughly.

Hank

Ned Flanders wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would check the timing first.

--
LSMFT

I haven't spoken to my wife in 18 months.
I don't like to interrupt her.

LSMFT wrote:
Ned Flanders wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it
(fresh gas, clean oil), but as soon as I pull on the throttle it
stalls. when it stalls I get a little blow back out of the throat of
the carburetor. Also if I take the oil cap off while it is running
there is blow back coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I
was just hoping someone might be able to point me in the right
direction. I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more
then the thing is worth.

I would check the timing first.

That was my first thought as well. Check to see if the sacrificial key is
at all anything other than pristine.

Jon

It's not worth taking in for repair as the labour would cost more
then the thing is worth.

Definitely, especially if it is something you can do yourself. I bought a
brand new Murray lawnmower a couple of weeks ago for $20 that the guy
couldn't get running, and all I did was clean the float bowl and stick a
needle in the jet.

I know nothing about your experience with external combustion engines. All
in all, they are fairly simple, and a one cylinder L head lawnmower is about
as simple as it gets, yet they ARE cranky, and any small obstruction or
problem will cause them not to work, and be very frustrating.

First, check and see if the spark plug is sparking. Take it out, put the
cable on there, and sit it on the metal around the hole it came out of. It
is much more fun if you have a brother-in-law or kid who will hold on to it
while you crank it, but they only fall for it once. Spin it and see if you
have a spark. No spark, that's your problem, and go from there.

If it is sparking, try priming it. Sometimes just the attempted starting of
a motor, or a short starting will suck loose the obstruction, or at least
get it running so you can further diagnose it.

That being said, priming and starting motors can be a very dangerous thing
to do. You basically do not want more than one cup of gasoline near what
you're doing. Drain the tank, or just tip the mower over, and get rid of
the gas in the tank. Smell it first. If it smells like gas, it's probably
good. If it smells like varnish, it needs to be dumped. Take off the air
cleaner, and with a short hose, or little eyedropper (or any equivalent,
like a ketchup squirter) put a LITTLE gas in the opening. Now be sure to
put the rest of the gas about ten feet away. Crank the motor, and see if
you can get it to do anything at all. If you get a sign of life, try to
prime it a couple of times and see if it will run.

If not, the next thing to do is to remove the float bowl. That is on the
bottom of the carburetor, and on lots, it is held in place by one central
bolt that is also the jet. Unscrew that and CAREFULLY take off the bowl,
trying not to screw up the gasket. Look in there and see if there is water
or crud. Wash it out with gas. Take a needle and insert it in the jet and
wash that with gas, too. On some models, it is held in place by four or
more screws, and you have to take the carb off the motor.

Here's where it gets complicated. If priming and checking the float bowl
don't solve your problem, you will probably have to take off the carb and
clean it. These are not rocket science, but they do have some small parts,
and intricate nuances. Sit out a towel on your work bench, and keep it
close down on the towel so that if a spring or rod or small part falls out,
you don't lose it.

They make carb rebuild kits for almost any small engine. Included in these
are gaskets, primer bulbs, and other things. By the time you get the carb
apart, you should be able to see something that is amiss, such as rust,
crud, a split primer bulb, cracked float, etc.

Now, on to the major components.

Could be cracked ring, burned valve, burned piston, seized piston, stuck
valve, broken valve, foreign matter keeping valve open, all sorts of stuff
that may either be fatal or easily changed.

Only you know what your capabilities are, but if you have a dead lawnmower,
what harm is it to pull the head and learn by doing an autopsy? Learn how
they work, and fiddle with the thing until you get how it works.

Most generally, unless the motor has been run without oil, it is a simple
carburetor problem. The timing is set because the flywheel is on a keyway,
and there is no ignition timing adjustment. It either fires or not.
Sometimes removing the flywheel, and sandpapering the components that
generate the spark solve the problem, or at least help by making the spark
more robust. Rust inside the area that creates the spark is a common
problem.

Small motors are simple yet challenging. And many times when you do find
the problem it's one of those DUH moments.

Unless you want to spend $50 or more and take it to a shop, most times you
can DIY, which is why we're here, isn't it?

No? ....................

Steve

visit my blog at http://cabgbypasssurgery.com watch for the book

A fool shows his annoyance at once, but a prudent man overlooks an insult.

On Jun 26, 11:22*pm, Ned Flanders
wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would start with a compression test. Gases coming fom the oil cap
usually indicates worn/broken piston rings, though if it's pretty old
you can expect worn rings. It may have been siezed up in the past due
to lack of oil. & someone's succeed in freeing it off. Check the
cylinder head bolts too.
It sounds to me like there's more than one fault which could arise if
the engine is old. If you check the compression & then put a little
oil in th spark plug hole and check again and the compression is up,
that indicates a ring problem. If not. it's likely to be the valves/
head gasket problem.

On Sat, 26 Jun 2010 22:56:52 -0700 (PDT), harry
wrote:

On Jun 26, 11:22*pm, Ned Flanders
wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would start with a compression test. Gases coming fom the oil cap
usually indicates worn/broken piston rings, though if it's pretty old
you can expect worn rings. It may have been siezed up in the past due
to lack of oil. & someone's succeed in freeing it off. Check the
cylinder head bolts too.
It sounds to me like there's more than one fault which could arise if
the engine is old. If you check the compression & then put a little
oil in th spark plug hole and check again and the compression is up,
that indicates a ring problem. If not. it's likely to be the valves/
head gasket problem.

Compr ession may well be bad, but my impression is that small engines
will usually run find with low compression, and the problem he needs
to fix is something else.

On Sat, 26 Jun 2010 15:22:23 -0700, Ned Flanders
wrote:

I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would suspect an engine problem first, because of the blow back.
However, my mini-tiller has a centrifugal clutch and geared
transmission. If yours is similar, are you sure the gearbox is filled
with grease to prevent seizing?

On Jun 27, 7:00*am, Gary Dyrkacz.
wrote:
On Sat, 26 Jun 2010 15:22:23 -0700, Ned Flanders

wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would suspect an engine problem first, because of the blow back.
However, my mini-tiller has a centrifugal clutch and geared
transmission. If yours is similar, are you sure the gearbox is filled
with grease to prevent seizing?

They all blow back if the oil cap is off. The downstroke of the pston
does it. And blowing back through the carb is not that odd either.
If it stops on an up compression stroke it can turn backwards.

s another poster mentioned, sounds like a fuel problem. If it's
starting then it's not ignition, the spark improves as the rpm go up.
Also as another person mentioned low compression makes them hard to
start. If you get one started they will run with pretty low
compression.

I'd remove the float bowl and check the main jet.

All good advice James.


"jamesgangnc" wrote in message
...
On Jun 27, 7:00 am, Gary Dyrkacz.
wrote:
On Sat, 26 Jun 2010 15:22:23 -0700, Ned Flanders

wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would suspect an engine problem first, because of the blow back.
However, my mini-tiller has a centrifugal clutch and geared
transmission. If yours is similar, are you sure the gearbox is filled
with grease to prevent seizing?

They all blow back if the oil cap is off. The downstroke of the pston
does it. And blowing back through the carb is not that odd either.
If it stops on an up compression stroke it can turn backwards.

s another poster mentioned, sounds like a fuel problem. If it's
starting then it's not ignition, the spark improves as the rpm go up.
Also as another person mentioned low compression makes them hard to
start. If you get one started they will run with pretty low
compression.

I'd remove the float bowl and check the main jet.

Johnl wrote:
All good advice James.


wrote in message
...
On Jun 27, 7:00 am, Gary
wrote:
On Sat, 26 Jun 2010 15:22:23 -0700, Ned Flanders

wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would suspect an engine problem first, because of the blow back.
However, my mini-tiller has a centrifugal clutch and geared
transmission. If yours is similar, are you sure the gearbox is filled
with grease to prevent seizing?

They all blow back if the oil cap is off. The downstroke of the pston
does it. And blowing back through the carb is not that odd either.
If it stops on an up compression stroke it can turn backwards.

s another poster mentioned, sounds like a fuel problem. If it's
starting then it's not ignition, the spark improves as the rpm go up.
Also as another person mentioned low compression makes them hard to
start. If you get one started they will run with pretty low
compression.

I'd remove the float bowl and check the main jet.




Ok, that makes sense (all the blow-back).

I appreciate all of the input. I plan on getting to it sometime this
week. I have to get a few things off my Honey-do-list first.

Thanks again everyone!

"mm" wrote in message
...
On Sat, 26 Jun 2010 22:56:52 -0700 (PDT), harry
wrote:

On Jun 26, 11:22 pm, Ned Flanders
wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

I would start with a compression test. Gases coming fom the oil cap
usually indicates worn/broken piston rings, though if it's pretty old
you can expect worn rings. It may have been siezed up in the past due
to lack of oil. & someone's succeed in freeing it off. Check the
cylinder head bolts too.
It sounds to me like there's more than one fault which could arise if
the engine is old. If you check the compression & then put a little
oil in th spark plug hole and check again and the compression is up,
that indicates a ring problem. If not. it's likely to be the valves/
head gasket problem.

Compr ession may well be bad, but my impression is that small engines
will usually run find with low compression, and the problem he needs
to fix is something else.

I bought a new Murray a couple of weeks ago for $20. It had a dirty float
bowl and jet. When I pulled the handle, I had to pull it VERY slowly to
feel any compression. I believe these are very low compression motors, and
function well at that compression.

Steve

visit my blog at http://cabgbypasssurgery.com watch for the book

A fool shows his annoyance at once, but a prudent man overlooks an insult.

On Sun, 27 Jun 2010 14:27:06 +0000 (UTC), Chief Two Eagles
wrote:

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

Hone the cylinder. Replace piston and rings to match the new diameter.
Might need to re-seat the valves using lap compound. Have to admit I've
never had a really small 4 stroke apart but it should follow the agenda
of larger 4 strokes.

A little extreme I think. It may need just a fuel / air mixture
adjustment.

On Jun 27, 4:26*pm, Oren wrote:
On Sun, 27 Jun 2010 14:27:06 +0000 (UTC), Chief Two Eagles

wrote:
It's not worth taking in for repair as the labour would cost more then
the thing is worth.

Hone the cylinder. Replace piston and rings to match the new diameter.
Might need to re-seat the valves using lap compound. Have to admit I've
never had a really small 4 stroke apart but it should follow the agenda
of larger 4 strokes.

A little extreme I think. It may need just a fuel / air mixture
adjustment.

That is not extreme at all, well maybe you don't have to hone the cyl.
much but you def. Have to clear it smooth an the piston and rings need
be checked n replced according.
A space age motor flush n lube could do the job if there is no lead to
suspect extreme wear or tear inside.

Years messing with ninibikes :-) an mowers makes anyone an expert in
4stroke jobs et al.
We always get them going strong again.
Good Luck !

On Sun, 27 Jun 2010 13:57:10 -0700 (PDT), Roy Quijano
wrote:

On Jun 27, 4:26*pm, Oren wrote:
On Sun, 27 Jun 2010 14:27:06 +0000 (UTC), Chief Two Eagles

wrote:
It's not worth taking in for repair as the labour would cost more then
the thing is worth.

Hone the cylinder. Replace piston and rings to match the new diameter.
Might need to re-seat the valves using lap compound. Have to admit I've
never had a really small 4 stroke apart but it should follow the agenda
of larger 4 strokes.

A little extreme I think. It may need just a fuel / air mixture
adjustment.

That is not extreme at all, well maybe you don't have to hone the cyl.
much but you def. Have to clear it smooth an the piston and rings need
be checked n replced according.

The OP did not mention changing the spark plug. Just reading the plug
can tell you about serious internal damage*. If the plug is fouling he
my very well have unburned gases coming from the carb/exhaust....

I would change / gap a new plug and try again. I would not be going
into the engine without some minor checks or adjustments (less
costly). YMMV

http://www.verrill.com/moto/sellingg...colorchart.htm

On Sun, 27 Jun 2010 08:16:45 -0700, "Steve B"
wrote:



I bought a new Murray a couple of weeks ago for $20. It had a dirty float
bowl and jet. When I pulled the handle, I had to pull it VERY slowly to
feel any compression. I believe these are very low compression motors, and
function well at that compression.

Steve

I guess my impression is based on the fact that it seems old cars and
old lawn mowers, when the rest is in good working order, seem to start
more easily than new ones. Cars turn over faster and mowers pull
eeaiser and they start right up.

This may have been much more noticable 20 or 30 years ago before
improvements in spark and fuel supplies

"mm" wrote in message
...
On Sun, 27 Jun 2010 08:16:45 -0700, "Steve B"
wrote:



I bought a new Murray a couple of weeks ago for $20. It had a dirty float
bowl and jet. When I pulled the handle, I had to pull it VERY slowly to
feel any compression. I believe these are very low compression motors,
and
function well at that compression.

Steve

I guess my impression is based on the fact that it seems old cars and
old lawn mowers, when the rest is in good working order, seem to start
more easily than new ones. Cars turn over faster and mowers pull
eeaiser and they start right up.

This may have been much more noticable 20 or 30 years ago before
improvements in spark and fuel supplies

Well, I agree with the spark, but the fuel supplies have gotten chintzier
with plastic elements that wear out or rot faster. Why did we not have
prime bulbs on the older ones? Just a choke. These new carb rebuild kits
are not rocket surgery, but they are a little fine. Some very little parts,
and if you get some grit in there, or get it a little off, you have to go
buy a new kit because you poked a hole in some delicate piece of plastic
clear gasket.

But I do have my new used $20 Snap on parts washer now, and that should make
things a little easier. That's a big thing to me, whether it be mowers, or
cars, or tractors. It's always nice to have a place inside where you can
keep it clean, elevate it to waist high working level, and have good
lighting and room to lay out the parts as they come off. And if you can't
put it together for a while, just put a cover or towel over it, and it will
keep the dust and sand out of it until you can come back and finish the job.

Steve

visit my blog at http://cabgbypasssurgery.com watch for the book

A fool shows his annoyance at once, but a prudent man overlooks an insult.

On Jun 28, 1:16*am, "Steve B" wrote:
"mm" wrote in message

...





On Sun, 27 Jun 2010 08:16:45 -0700, "Steve B"
wrote:

I bought a new Murray a couple of weeks ago for $20. *It had a dirty float
bowl and jet. *When I pulled the handle, I had to pull it VERY slowly to
feel any compression. *I believe these are very low compression motors,
and
function well at that compression.

Steve

I guess my impression is based on the fact that it seems old cars and
old lawn mowers, when the rest is in good working order, seem to start
more easily than new ones. *Cars turn over faster and mowers pull
eeaiser and they start right up.

This may have been much more noticable 20 or 30 years ago before
improvements in spark and fuel supplies

Well, I agree with the spark, but the fuel supplies have gotten chintzier
with plastic elements that wear out or rot faster. *Why did we not have
prime bulbs on the older ones? *Just a choke. *These new carb rebuild kits
are not rocket surgery, but they are a little fine. *Some very little parts,
and if you get some grit in there, or get it a little off, you have to go
buy a new kit because you poked a hole in some delicate piece of plastic
clear gasket.

But I do have my new used $20 Snap on parts washer now, and that should make
things a little easier. *That's a big thing to me, whether it be mowers, or
cars, or tractors. *It's always nice to have a place inside where you can
keep it clean, elevate it to waist high working level, and have good
lighting and room to lay out the parts as they come off. *And if you can't
put it together for a while, just put a cover or towel over it, and it will
keep the dust and sand out of it until you can come back and finish the job.

Steve

visit my blog athttp://cabgbypasssurgery.comwatch for the book

A fool shows his annoyance at once, but a prudent man overlooks an insult..- Hide quoted text -

- Show quoted text -

Mostly the prime bulbs are on diaphram carbs. And that's because the
carb is also a fuel pump. They've always had little parts and tiny
orifices, that's just the nature of a carb for an engine that small.
I don't see that much has changed, you've always needed to be careful
rebuilding carbs.

On Jun 26, 5:22*pm, Ned Flanders wrote:
I have a small tiller I bought second had - 4 stroke. It ran well the
first year and then it developed a small problem. I can start it (fresh
gas, clean oil), but as soon as I pull on the throttle it stalls. when
it stalls I get a little blow back out of the throat of the carburetor.
Also if I take the oil cap off while it is running there is blow back
coming out of there as well.

I am not afraid to rip it down, as I can do minor engine repairs. I was
just hoping someone might be able to point me in the right direction.

I am thinking a gasket...

It's not worth taking in for repair as the labour would cost more then
the thing is worth.

A compression test is the cheapest and easiest thing to do to find out
about a motors condition and life left, If I were shopping for
something used I would carry a tester and wrench. Smoke out of oil
means nothing yet, it could be many simple things like a dirty carb,
flywheel key, coil, ignition module, and as simple as a bad plug wire
or plug that fails to carry full current under load but will idle, ive
had all these things happen. Was any gas left in the carburator over
the winter, empting the tank doesnt empty the carb, if gas was left
in, then the carb is what I would do first.

On Jun 28, 10:24*am, ransley wrote:

A compression test is the cheapest and easiest thing to do to find out
about a motors condition and life left, If I were shopping for
something used I would carry a tester and wrench. Smoke out of oil
means nothing yet, it could be many simple things like a dirty carb,
flywheel key, coil, ignition module, and as simple as a bad plug wire
or plug that fails to carry full current under load but will idle, ive
had all these things happen. Was any gas left in the carburator over
the winter, empting the tank doesnt empty the carb, if gas was left
in, then the carb is what I would do first.

If it starts and runs, if only for a minute, the timing is ok. Timing
doesn't change under normal circumstances. Spark plugs can operate
under a "no Load" condition, and fail under a load. He obviously has
an air/fuel mixture problem.

Hank

On Jun 28, 9:59*am, "Hustlin' Hank" wrote:
On Jun 28, 10:24*am, ransley wrote:

A compression test is the cheapest and easiest thing to do to find out
about a motors condition and life left, If I were shopping for
something used I would carry a tester and wrench. Smoke out of oil
means nothing yet, it could be many simple things like a dirty carb,
flywheel key, coil, ignition module, and as simple as a bad plug wire
or plug that fails to carry full current under load but will idle, ive
had all these things happen. Was any gas left in the carburator over
the winter, empting the tank doesnt empty the carb, if gas was left
in, then the carb is what I would do first.

If it starts and runs, if only for a minute, the timing is ok. Timing
doesn't change under normal circumstances. Spark plugs can operate
under a "no Load" condition, and fail under a load. He obviously has
an air/fuel mixture problem.

Hank

He said it fails under throttle, to me that means many things that it
could be, but the most logical is he left gas in the carb.

On Jun 28, 1:00*pm, ransley wrote:
On Jun 28, 9:59*am, "Hustlin' Hank" wrote:





On Jun 28, 10:24*am, ransley wrote:

A compression test is the cheapest and easiest thing to do to find out
about a motors condition and life left, If I were shopping for
something used I would carry a tester and wrench. Smoke out of oil
means nothing yet, it could be many simple things like a dirty carb,
flywheel key, coil, ignition module, and as simple as a bad plug wire
or plug that fails to carry full current under load but will idle, ive
had all these things happen. Was any gas left in the carburator over
the winter, empting the tank doesnt empty the carb, if gas was left
in, then the carb is what I would do first.

If it starts and runs, if only for a minute, the timing is ok. Timing
doesn't change under normal circumstances. Spark plugs can operate
under a "no Load" condition, and fail under a load. He obviously has
an air/fuel mixture problem.

Hank

*He said it fails under throttle, to me that means many things that it
could be, but the most logical is he left gas in the carb.-

That would be my first place to look too. As I stated, an air-to-fuel
ratio problem, which is usually caused by a dirty carb, or some
restricted fuel flow problem. But, we'll probably never know.

Hank

On Jun 27, 5:55*pm, Oren wrote:
On Sun, 27 Jun 2010 13:57:10 -0700 (PDT), Roy Quijano





wrote:
On Jun 27, 4:26*pm, Oren wrote:
On Sun, 27 Jun 2010 14:27:06 +0000 (UTC), Chief Two Eagles

wrote:
It's not worth taking in for repair as the labour would cost more then
the thing is worth.

Hone the cylinder. Replace piston and rings to match the new diameter..
Might need to re-seat the valves using lap compound. Have to admit I've
never had a really small 4 stroke apart but it should follow the agenda
of larger 4 strokes.

A little extreme I think. It may need just a fuel / air mixture
adjustment.

That is not extreme at all, well maybe you don't have to hone the cyl.
much but you def. Have to clear it smooth an the piston and rings need
be checked n replced according.

The OP did not mention changing the spark plug. Just reading the plug
can tell you about serious internal damage*. If the plug is fouling he
my very well have unburned gases coming from the carb/exhaust....

I would change / gap a new plug and try again. I would not be going
into the engine without some minor checks or adjustments (less
costly). YMMV

http://www.verrill.com/moto/sellingg...colorchart.htm

Sure, a basic tune up could be the solution...

Hustlin' Hank wrote:
On Jun 28, 1:00 pm, wrote:
On Jun 28, 9:59 am, "Hustlin' wrote:





On Jun 28, 10:24 am, wrote:

A compression test is the cheapest and easiest thing to do to find out
about a motors condition and life left, If I were shopping for
something used I would carry a tester and wrench. Smoke out of oil
means nothing yet, it could be many simple things like a dirty carb,
flywheel key, coil, ignition module, and as simple as a bad plug wire
or plug that fails to carry full current under load but will idle, ive
had all these things happen. Was any gas left in the carburator over
the winter, empting the tank doesnt empty the carb, if gas was left
in, then the carb is what I would do first.

If it starts and runs, if only for a minute, the timing is ok. Timing
doesn't change under normal circumstances. Spark plugs can operate
under a "no Load" condition, and fail under a load. He obviously has
an air/fuel mixture problem.

Hank

He said it fails under throttle, to me that means many things that it
could be, but the most logical is he left gas in the carb.-

That would be my first place to look too. As I stated, an air-to-fuel
ratio problem, which is usually caused by a dirty carb, or some
restricted fuel flow problem. But, we'll probably never know.

Hank

Well I reset the spark plug gap, rocker arm clearances, cleaned and
re-oiled the air filter - so now it idles fantastic. Unfortunately it
still stalls on full throttle.

I plan on pulling off the carb next. The spark plug was covered in
carbon so its probably a fuel mixture problem.

timing

timing

On Sunday, December 13, 2015 at 10:46:00 AM UTC-6, wrote:
timing

timing...? or maybe timing?

Have you taken the fuel line off the carburetor?? A partially clogged fuel line can supply enough gas to idle ok, but starve at a higher speed where there is more air flowing, but not more gas.