On Mon, 18 Oct 2010 20:52:05 -0700, "Steve B"
wrote:


"Oren" wrote
.


The spark ignition happens at the top of the compression stroke TDC
(valves closed). When fuel/air is compressed and fired piston drops
to BDC ready for the exhaust stroke (valves open). No?

No. Spark happens, piston travels to bottom, on the upstroke, the exhaust
valve opens, piston comes up, pushes out spent gas, at TDC, intake valve
opens, piston drops pulling in air, comes up on compression stroke, and a
few degrees BTDC, fires again. One spark per two full revolutions of crank.

Steve


The four strokes of a four stroke engine in living ASCII art

http://www.repairfaq.org/samnew/lmfaq/lmtfsofse.htm

I still call the compression stroke the power stroke --even if firing
at BTDC or TDC. I think we get it.

The engines I've serviced, the camshaft rotates once for each rotation
of the crank shaft. A "stroke" is the motion of the piston, either up
or down. I think the confusion may be lingering.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Oren" wrote in message
...

I think it's a misnomer to call a crank rotation a "stroke." The four
strokes of a four-stroke ICE are as noted, so you get power on every
fourth stroke. I can't tell from your post whether you agree with
that.

The poster confused me a little (nothing permanent).

The lobe on the crank/cam still needs to turn four times... thus four
strokes.

I've always called it: intake, compression, power and exhaust.
Counting combustion the same as the power stroke.

Four stroke fires, every second rotation of the crank shaft. You
described it pretty much the way I was taught. Same with your
description of two stroke.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Steve B" wrote in message
...


Am I mistaken, or does a "four stroke" fire on every other rotation?
The
ignition spark powers the crank down from a few degrees BTDC for power
with
all valves closed, and the upcoming piston pushes out the exhaust with
the
exhaust valve open. When it reaches TDC, the downward traveling
piston
sucks in gas through the open/opening intake valve, and when it
reaches its
designated firing degree BTDC, it fires. Every other stroke.

With a two stroke, the spark plug fires every rotation, with the
intake and
exhaust being achieved by a porting system routing gas and exhaust on
different sides of the piston.

Class?

Class?

Steve

Heart surgery pending?
Read up and prepare.
Learn how to care for a friend.
http://cabgbypasssurgery.com

Of course, the same term can refer to different meanings. I think your
meaning is also correct.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Tegger" wrote in message
...
"Steve B" wrote in
:



Am I mistaken, or does a "four stroke" fire on every other rotation?



You're all mistaken.

A "four stroke" is a teenage boy. That's how many strokes it takes him
to
"fire" when viewing online female-anatomical matter.


--
Tegger

Worth noting. There are actually two sparks, per fire. One spark is at
TDC when the gasses are compressed. The second spark is also at TDC at
the end of the exhaust stroke. The second spark is wasted, but does no
damage.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Steve B" wrote in message
...

The spark ignition happens at the top of the compression stroke TDC
(valves closed). When fuel/air is compressed and fired piston drops
to BDC ready for the exhaust stroke (valves open). No?

No. Spark happens, piston travels to bottom, on the upstroke, the
exhaust
valve opens, piston comes up, pushes out spent gas, at TDC, intake
valve
opens, piston drops pulling in air, comes up on compression stroke,
and a
few degrees BTDC, fires again. One spark per two full revolutions of
crank.

Steve

Thanks for the link, that's fun.

If you want to talk with other mechanics, it would be wise to call the
compression and power strokes different things. The compression stroke
is the one before the power stroke.

Intake
Compression
Power
Exhaust

(in that order)

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Oren" wrote in message
...


The four strokes of a four stroke engine in living ASCII art

http://www.repairfaq.org/samnew/lmfaq/lmtfsofse.htm

I still call the compression stroke the power stroke --even if firing
at BTDC or TDC. I think we get it.

"Steve B" ) writes:
"Oren" wrote
.



The spark ignition happens at the top of the compression stroke TDC
(valves closed). When fuel/air is compressed and fired piston drops
to BDC ready for the exhaust stroke (valves open). No?


No. Spark happens, piston travels to bottom, on the upstroke, the exhaust
valve opens, piston comes up, pushes out spent gas, at TDC, intake valve
opens, piston drops pulling in air, comes up on compression stroke, and a
few degrees BTDC, fires again. One spark per two full revolutions of crank.


Simple small four stroke engines (lawnmowers etc.) spark every crank
revolution. The spark is usually triggered by the crankshaft on small
four stroke engines. Larger four stroke engines (automobiles) spark
every second crank revolution per cylinder. The spark is usually triggered
by the camshaft on large four stroke engines. The camshaft rotates
at half the speed of the crankshaft.



Steve

"Smitty Two" wrote in message
Here's what I remember from building the "Visible V-8" model when I was
a kid: intake, compression, combustion (power), exhaust. I count power
on every fourth stroke.

Yes, what I said was somewhat misleading. On a two stroke cycle, you get
a power stroke on every stroke. There is a power stroke integrated with
an exhaust stroke (going down) and intake and compression integrated
on the upward stroke. But these are two strokes...down and up.
On a four stroke cycle, you have two downward strokes and two
upward strokes, only only one of which is a power stroke.

So for one revolution of a two stroke, you get a power stroke: for two
revolutions of a four stroke cycle, you get a power stroke.

"Tegger" wrote in message
You're all mistaken.

A "four stroke" is a teenage boy. That's how many strokes it takes him to
"fire" when viewing online female-anatomical matter.

Yeah, that is what Cuhulin was talking about with his 6 stroke
situation.. It gets that way when you get old.

"Oren" wrote in message I think we get it.

Maybe.. You still get twice as many power strokes with a two stroke
cycle engine as you do with a four stroke cycle engine, RPM being
the same.

On Thursday, August 19, 2010 at 3:57:45 PM UTC-4, SF Man wrote:
Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

Ever since it was new, my two-stroke Sears Craftsman 358351.800 18" 40cc
chain saw has been miserable to start and even worse to run. Even when new,
I could never release my finger on the trigger for fear of the Craftsman
chainsaw conking out and not restarting for another 20 minutes of pulling
the string.

The Sears Craftsman 358351 chain saw is now about a year old, and I've got
only about 3 or 4 hours on it (a few tanks of gas and bar oil) but it now
won't even start anymore except when left overnight. Even then, it only
runs until I lift my finger off the trigger and it conks out and won't
start again. I'm so sorry I didn't read Craftsman chain saw reviews because
I'm sure this is a design flaw (maybe because it's a California low-smog
chainsaw?).

Anyway, I'm stuck with it.

I replaced the Champion RCJ7Y spark plug, the felt air filter, and put a
newly bought newly mixed 40:1 gasolineil mixture in the tank; but it's
STILL hard to start.

Following owners manual instructions, I set the choke to full on, I press
the accelerator pump 6x, I pull the starter cord 5 times, I set the choke
to 1/2 position, I pull the starter cord a half dozen more times, and, more
often than not, it does not start.

I called Sears' 800 number but they only sell parts; the guy told me to
tune the carbeurator but I don't know what that procedure is.

Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

I have a Model 358 352180 18" Crapsman chainsaw too and it will not even pop with primer. I have worked on small engines for years and this is the first one that stumped me this bad. I did find they had the primer hoses on backwards and I corrected that but it has spark, compression and fuel and it should at least pop. The one last thing to check is the key in the flywheel.. If that is sheared the least bit, it will not fire. If that is okay, the saw goes in the dumpster on trash day! I should know better than to buy new Crapsman power tools ..gas or electric!! They have gone way down hill since the old days!!

On Wednesday, April 27, 2016 at 4:08:58 PM UTC-5, wrote:

I have a Model 358 352180 18" Crapsman chainsaw too and it will not even pop with primer. I have worked on small engines for years and this is the first one that stumped me this bad. I did find they had the primer hoses on backwards and I corrected that but it has spark, compression and fuel and it should at least pop. The one last thing to check is the key in the flywheel. If that is sheared the least bit, it will not fire. If that is okay, the saw goes in the dumpster on trash day! I should know better than to buy new Crapsman power tools ..gas or electric!! They have gone way down hill since the old days!!

....I've never heard of a sheared key on a saw. Try a minute spray of carb cleaner down the throat of the cab...to see if it will pop. If it pops, get a carb rebuilding kit for it.

On Wed, 27 Apr 2016 14:08:54 -0700 (PDT), wrote:

On Thursday, August 19, 2010 at 3:57:45 PM UTC-4, SF Man wrote:
Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

Ever since it was new, my two-stroke Sears Craftsman 358351.800 18" 40cc
chain saw has been miserable to start and even worse to run. Even when new,
I could never release my finger on the trigger for fear of the Craftsman
chainsaw conking out and not restarting for another 20 minutes of pulling
the string.

The Sears Craftsman 358351 chain saw is now about a year old, and I've got
only about 3 or 4 hours on it (a few tanks of gas and bar oil) but it now
won't even start anymore except when left overnight. Even then, it only
runs until I lift my finger off the trigger and it conks out and won't
start again. I'm so sorry I didn't read Craftsman chain saw reviews because
I'm sure this is a design flaw (maybe because it's a California low-smog
chainsaw?).

Anyway, I'm stuck with it.

I replaced the Champion RCJ7Y spark plug, the felt air filter, and put a
newly bought newly mixed 40:1 gasolineil mixture in the tank; but it's
STILL hard to start.

Following owners manual instructions, I set the choke to full on, I press
the accelerator pump 6x, I pull the starter cord 5 times, I set the choke
to 1/2 position, I pull the starter cord a half dozen more times, and, more
often than not, it does not start.

I called Sears' 800 number but they only sell parts; the guy told me to
tune the carbeurator but I don't know what that procedure is.

Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

There is a fuel filter in the gas tank. Check it...

You say there is a spark, in the spark plug, or just from the wire going to the spark plug. Have you tried a new spark plug, they do crap out especially in 2-stroke engines which is what I believe you have in your saw.

On Wed, 27 Apr 2016 23:08:47 -0400, wrote:

On Wed, 27 Apr 2016 14:08:54 -0700 (PDT), wrote:

On Thursday, August 19, 2010 at 3:57:45 PM UTC-4, SF Man wrote:
Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

Ever since it was new, my two-stroke Sears Craftsman 358351.800 18" 40cc
chain saw has been miserable to start and even worse to run. Even when new,
I could never release my finger on the trigger for fear of the Craftsman
chainsaw conking out and not restarting for another 20 minutes of pulling
the string.

The Sears Craftsman 358351 chain saw is now about a year old, and I've got
only about 3 or 4 hours on it (a few tanks of gas and bar oil) but it now
won't even start anymore except when left overnight. Even then, it only
runs until I lift my finger off the trigger and it conks out and won't
start again. I'm so sorry I didn't read Craftsman chain saw reviews because
I'm sure this is a design flaw (maybe because it's a California low-smog
chainsaw?).

Anyway, I'm stuck with it.

I replaced the Champion RCJ7Y spark plug, the felt air filter, and put a
newly bought newly mixed 40:1 gasolineil mixture in the tank; but it's
STILL hard to start.

Following owners manual instructions, I set the choke to full on, I press
the accelerator pump 6x, I pull the starter cord 5 times, I set the choke
to 1/2 position, I pull the starter cord a half dozen more times, and, more
often than not, it does not start.

I called Sears' 800 number but they only sell parts; the guy told me to
tune the carbeurator but I don't know what that procedure is.

Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

There is a fuel filter in the gas tank. Check it...


You can get a carburetor for less than $30 and that will fix most of
these hard to start, won't run problems.
http://www.searspartsdirect.com/part.../0071/358.html

wrote:
On Wed, 27 Apr 2016 23:08:47 -0400, wrote:

On Wed, 27 Apr 2016 14:08:54 -0700 (PDT),
wrote:

On Thursday, August 19, 2010 at 3:57:45 PM UTC-4, SF Man wrote:
Do you know where to find the tune-up procedure for the Sears
Craftsman 358.351.800 18 inch chain saw?

Ever since it was new, my two-stroke Sears Craftsman 358351.800
18" 40cc chain saw has been miserable to start and even worse to
run. Even when new, I could never release my finger on the trigger
for fear of the Craftsman chainsaw conking out and not restarting
for another 20 minutes of pulling the string.

The Sears Craftsman 358351 chain saw is now about a year old, and
I've got only about 3 or 4 hours on it (a few tanks of gas and bar
oil) but it now won't even start anymore except when left
overnight. Even then, it only runs until I lift my finger off the
trigger and it conks out and won't start again. I'm so sorry I
didn't read Craftsman chain saw reviews because I'm sure this is a
design flaw (maybe because it's a California low-smog chainsaw?).

Anyway, I'm stuck with it.

I replaced the Champion RCJ7Y spark plug, the felt air filter, and
put a newly bought newly mixed 40:1 gasolineil mixture in the
tank; but it's STILL hard to start.

Following owners manual instructions, I set the choke to full on,
I press the accelerator pump 6x, I pull the starter cord 5 times,
I set the choke to 1/2 position, I pull the starter cord a half
dozen more times, and, more often than not, it does not start.

I called Sears' 800 number but they only sell parts; the guy told
me to tune the carbeurator but I don't know what that procedure is.

Do you know where to find the tune-up procedure for the Sears
Craftsman 358.351.800 18 inch chain saw?

There is a fuel filter in the gas tank. Check it...


You can get a carburetor for less than $30 and that will fix most of
these hard to start, won't run problems.
http://www.searspartsdirect.com/part.../0071/358.html

I suspect he's fighting an extremely lean condition . Kalifornistan has
them set the damn things so lean they'll barely run , the cure is to open up
the low and high speed needle valves a bit . The problem is that "they"
don't want you to do that , so they make the adjustment screws so you need a
special tool to adjust them . My solution (Ryobi weedeater) was to use my
dremel with a cutoff wheel to cut a slot for a regular screwdriver in the
head . Runs swell now ... but I still can't get the neighbor's Stihl to run
right ...

--
Snag

On Thursday, August 19, 2010 at 3:57:45 PM UTC-4, SF Man wrote:
Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

Ever since it was new, my two-stroke Sears Craftsman 358351.800 18" 40cc
chain saw has been miserable to start and even worse to run. Even when new,
I could never release my finger on the trigger for fear of the Craftsman
chainsaw conking out and not restarting for another 20 minutes of pulling
the string.

The Sears Craftsman 358351 chain saw is now about a year old, and I've got
only about 3 or 4 hours on it (a few tanks of gas and bar oil) but it now
won't even start anymore except when left overnight. Even then, it only
runs until I lift my finger off the trigger and it conks out and won't
start again. I'm so sorry I didn't read Craftsman chain saw reviews because
I'm sure this is a design flaw (maybe because it's a California low-smog
chainsaw?).

Anyway, I'm stuck with it.

I replaced the Champion RCJ7Y spark plug, the felt air filter, and put a
newly bought newly mixed 40:1 gasolineil mixture in the tank; but it's
STILL hard to start.

Following owners manual instructions, I set the choke to full on, I press
the accelerator pump 6x, I pull the starter cord 5 times, I set the choke
to 1/2 position, I pull the starter cord a half dozen more times, and, more
often than not, it does not start.

I called Sears' 800 number but they only sell parts; the guy told me to
tune the carbeurator but I don't know what that procedure is.

Do you know where to find the tune-up procedure for the Sears Craftsman
358.351.800 18 inch chain saw?

I just got a new craftsman chainsaw today and its a bitch to start.. I was thinking it had some hidden safety switch that was open but eventually I started it. It sounds like you dont know much about small engines judging by your comments so get a friend who has some knowledge on these things. The carb has two adjustment screws, Im guessing for high and low speed running, tell whoever works on it to start there. Good luck with it

On Tuesday, April 9, 2019 at 9:04:12 PM UTC-4, wrote:
I just got a new craftsman chainsaw today and its a bitch to start. I was thinking it had some hidden safety switch that was open but eventually I started it. It sounds like you dont know much about small engines judging by your comments so get a friend who has some knowledge on these things. The carb has two adjustment screws, Im guessing for high and low speed running, tell whoever works on it to start there. Good luck with it"

Yeah, and then tell the friend that you can't fiddle with those carb screws
without having the proper keyed tool which isn't so easy to get. And those
screws are probably behind plastic caps that once removed, will make it
obvious that you screwed with it, so they may not take it back. It's an
old thread, but if i got a "new" chainsaw and it's hard to start, I would
take it back.

On 4/10/19 5:22 AM, trader_4 wrote:
On Tuesday, April 9, 2019 at 9:04:12 PM UTC-4, wrote:
I just got a new craftsman chainsaw today and its a bitch to start. I was thinking it had some hidden safety switch that was open but eventually I started it. It sounds like you dont know much about small engines judging by your comments so get a friend who has some knowledge on these things. The carb has two adjustment screws, Im guessing for high and low speed running, tell whoever works on it to start there. Good luck with it"
Yeah, and then tell the friend that you can't fiddle with those carb screws
without having the proper keyed tool which isn't so easy to get. And those
screws are probably behind plastic caps that once removed, will make it
obvious that you screwed with it, so they may not take it back. It's an
old thread, but if i got a "new" chainsaw and it's hard to start, I would
take it back.


Stihl - Problem solved.