I accidentally found I could test if the fuel line was clogged by pressing
the accelerator pump bulb a few times with the two or three inch fuel hose
out of the tank in the air with the filter attached.
The gas in the line went into the bulb until the line was dry as I
continually pressed the bulb.
Then I dropped the attached fuel filter into the gas tank and continued to
press the bulb a few times and it filled up with gas.
So, the fuel filter and fuel line aren't clogged. BTW, in hindsight, I knew
this because the bulb filled with gas every time. If the fuel line were
clogged, I would think the bulb would have been harder to fill with gas.
Anyway, it's not the fuel line in the tank. And, it's not the spark to the
plug. So, I'm pretty much left with the fuel ratio at this point.
I guess it could be compression or timing.
Is there a test for two-stroke compression & timing?
With the starter cord removed in the Craftsman 18 inch chain saw
(358351800), I cleaned things out and noticed there are three separate fuel
lines; but they all seem clear.
1. The thinner fuel line starts at the filter in the gas tank and goes to
the bottom of the carbeurator.
2. It comes out the side of the carb with a thicker line and goes into the
accelerator pump bulb.
3. Then it comes out of the accelerator pump bulb, again with a thicker
line, and ends up near the choke plate.
There are two side-by-side plates; one is for the throttle; the other is
for the choke. They appear to be working properly when I manipulate the
controls. The choke plate has a hole drilled in it so you can't totally
choke off the air.
So far, I can only find ONE screw with a spring on it which seems to be an
adjusting screw. I will go back and look for the other.
BTW, I tested 'compression' with my thumb as I pulled on the starter cord
before removing it and there was only a slight puff ... I wonder how to
test compression and timing on a two stroke?
Do these things have points?
The one adjusting screw seems to be at the level of the choke.
Surprisingly, I counted 8 full revolutions before it bottomed out.
I'm SURPRISED because I was expecting only one or two turns based on the
adjustment procedure people said here (to back it out one turn).
Does 8 turns to bottom the adjusting screw for the choke plate seem odd to
you? Should I still just back it out ONE turn?
I looked all over. Maybe because it's a California chain saw, but I only
see a single adjustment screw near the choke plate. Not two adjusting
I screwed it out 1 1/2 turns.
Also I removed, as suggested, the baffle plate on the exhaust and the brass
screen, both of which were sooty but otherwise wholly clear.
I'll see if that works.
Oh oh. I read warnings about running two strokes too rich or at wide-open
throttle. I run it at full throttle all the time (if I don't, it stalls).
Is that bad?
Anyway, I figured I'd better google for Poulan carb adjustment procedures:
Will try that.
BTW, I learned in this video that the low and high have H and L stamped on
them. Will look for that first.
timing is set by the flywheel key and usually not adjustable. They are
usually pretty trouble free.
What you can do is squirt some carb cleaner into the carb throat and
that should get it to start for just a second maybe two. If it does and
you know you are getting gas to the carb then you will have to clean the
carburetor. The metering holes are very very small and it doesn't take
much to clog them. One side of the carb is the fuel pump. The other
side meters the gas to the engine. First I'd spray a little carb
cleaner or a little gasoline into the carb and make sure the engine will
start and run just a bit. Then the carburetor cleaning. Since it's
only a year old the gaskets and diaphragms ought to still be good. The
metering holes and jets are very small (emissions control) two strokes
are considered dirty burning and the carburetors are made so you can't
over richen the mixture which is what you really need at times. Anyway
I've gotten small engines to run by priming them directly with gasoline
or carb cleaner even WD 40 sprayed into the carburetor throat and if you
can just get it to "pop" and run sometimes that will be enough to get
things working enough to continue running. The screw that was backed
out 8 turns probably doesn't matter since the carbs are now fixed with
such metering holes. You will have to make sure those are clear when
you have the carb apart spray carb cleaner into all the little holes and
use compressed air to blow them out, there is a small screen also but
those are usually not the problem. Old fuel is usually the problem it
coats things with varnish and gum.
You might get this thing running yet. Some of the youtube videos are
On Sat, 21 Aug 2010 15:57:48 -0500, FatterDumber& Happier Moe wrote:
This is an excellent treatise. It explains a lot, e.g., why I can't find
the L and H carb screws (they're pinned apparently). And why the T screw
didn't do anything useful.
BTW, I tried to "listen" for the snap of the spark across the gap but you
just can't hear it because of the noise made while you're pulling the
starter so that snap test will always fail. But, I can "see" the spark
easily so I'm gonna assume it's the air:fuel ratio.
I guess it's time to take the carb apart. I have MAF cleaner in stock
(xylene) but not carb cleaner, so, I'll have to stop off at the store about
15 miles away to go and get it.
On Sun, 22 Aug 2010 15:25:33 -0400, Stormin Mormon wrote:
That's a good point. It does spin easier (much easier) with the plug out.
Also, I tried blowing abouit 50psi compressed air into the spark plug hole
... with mixed results.
- If the piston was at the top, it fluttered.
- If the piston was at another spot, it blew out the exhaust.
- If the piston was at yet another spot, it blew out the carbeurator.
But it never did run the thing (I think because of the pull-cord clutch
mechanism because it 'looked' like it wanted to spin but couldn't spin.
Probably because it wasn't fast enough to make the pull-cord clutch
Doh. I just realized the "L", "H", and "T" embossed on the cover that I
first removed indicated the low, high, and ... hmmm ... I guess "throttle"
Both the "L" and the "H" pin are NOT screws. Clearly they are not designed
to be adjusted. Again, this may be a California (smog) thing. To discourage
you from touching them, there is a point instead of a screw slot; and they
have a housing around them just so you can't easily get to them.
The "T" screw is easy to get to, even with all the covers on as there is a
slot in the plastic to allow access. Do you think the "T" is for throttle?
If the T is for throttle - that may just fix your idle problem.
Is that the screw with the spring? When adjusting a screw, on the
carb, count the number of turns it takes to seat the screw. Not tight,
but just seated.
Back the screw out shy or past the number you wrote down.
Get it running and adjust a second time...
The last time I held Sears to their gaurantee was on a Craftman
electric weed eater. The design was such that after new line was let
out via the bump line release (which worked pretty well), a blade on a
plastic bracket was suppose to cut the line to proper length while it
was spinning. The down side was, the design was such that it was a
crap shot as to whether the new line would hit the bracket or the
blade. If it hit the bracket, the bracket was flimsey enough to snap
Sure enough, eventually the new line took out the braket and blade
together and I returned the entire unit to Sears, whereupon the gave
me a brand new trimmer, no questions asked. Sweet. Unfortunately, the
design had not changed and after about and hour of hard use with the
new trimmer, the line whacked off the entire bracket once again.
Perhaps their gaurantee no longer applies to "moving part" tools as
you suggest, but it matters not. That was 30 yrs ago and the last
Craftman tool I've ever bought other than an occasional screwdriver or
In all fairness, those "driver" hand tools are pretty good for the
price. They also used to make awesome roll-away tool boxes. I once
worked at a small start-up company that had a dozen mech-techs sharing
the company's tools out of a couple Craftsman roll-away tool boxes.
Those boxes were abused unmercifully, drawers being yanked open and
slammed shut a thousand times per day. I was in awe of how well they
held up and ending up buying a pair for myself. I still have it and
it's an excellent product. I can't say if they are still as well
I once showed a friend of mine a good way to check the ignition of a two
cycle engine. I stuck an air hose into the empty spark plug hole and
pressurized the cylinder then pulled the starter rope. The little motor
ran happily on compressed air and the ignition system put out a nice big
spark. It blew his mind (no pun). We set all of the needle valves in
accordance with the manual, it indicated the number of turns
the needle valves needed to be backed off from being fully seated.
Of course, we cleaned everything first, making sure nothing was stopped
up. After all our machinations, the little two cycle started on the
I just realized that just before it stopped running, it ran really really
fast. Of course, I had protective headgear on, but, even then, thinking
back, it was running really fast.
I wonder ...
I wonder if I blew the rings somehow.
When I put my finger over the hole after removing the spark plug, and
pulled the starter cord, there was only a small puff. Noticeable. But
Do you think compression might be the problem?
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