Poulan's Wild thing 42cc . Uggg

If you're confident in your compression gauge, then forget it. 92psi is very low. It's sometimes possible to get a saw with low compression to run, briefly and badly, but it won't do any serious work for you and it will soon stop entirely.

On the other hand if you're not sure of the gauge then I'd pull the muffler and look at the piston directly. If it's scored then it's probably not worth going any further.

Then I'll assume your compression gauge is either no good, or not an appropriate type for small engine work. It's unlikely the compression is down near 92 if the piston looks good.

The next thing I'd do is confirm that you've got spark. Remove the spark plug, fit it into the spark plug boot, move to a dark area, ground the plug against the cylinder (hold the wire or boot, not the metal part of the plug), and pull the rope a few times. You should see obvious sparks jumping across the electrodes.

If you've got spark, I'd put the saw back together, fuel it up, pull the rope several times and then immediately remove the plug again and look at its business end. If the electrodes are wet, then fuel is getting into the motor. If it's dry, then you will have narrowed it to a fuel delivery problem.

+1 on make sure you're getting an accurate pressure reading. I had a $15 Harbor Freight gauge. One of my great running Husky 55 read 85 PSI. I'm like "How can it run????". then got a $45 Actron gauge - it read 170 PSI.
A simple test is: Hold saw up by rope handle, let saw go...Does saw drop Lug........Lug........Lug. =good. Or saw drops Lug..Lug..Lug = bad.

$80 seems quite steep for a Wild Thing. I give $10 (or $15 if case included) for a non runner. I don't see carb work mentioned....bet the carb needs cleaning and rebuild kit. Or a new AfterMarket carb. A Walbro WT-891 clone is ~$10. A Partner 350 carb works after a little grinding on the choke rod plate so it doesn't hit air filter bracket. Partner 350 carb can be had for $6 on ebay auction. Now, I'm discussing 1990-2005 Poulans = before strato.

Perfect choice. You will soon forget about the wild thing.

Jags said:

Not fair. It still may be perfectly usable as a wheel chock or to throw at a crazed ground hog.

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I doubt it, too heavy to toss and too much plastic to really be an effective wheel chock.

sorry, not a fan of poulin. overall the modern stuff is garbage. me and a couple of the other guys have gotten them where the carbs just go batshit crazy for no apparent reason. I mean they will be adjusted perfect 1 minute and start em tomorrow and the adjustments are off. way off.

I had one, you get it running perfectly and it wouldn't start like that. get it to where it started easily and it ran like crap.

I've never had a complaint about one of my makitas or hiltis. I had my 4 stroke Makita concrete saw firing on one pull.

in any case... how are you testing compression? start it from empty, 3 quick pulls and read it.

try spraying wd40 in it and then test compression again. if it doesn't move the gauge aint working so well. if it goes up, your rings might be having some issues. 90 is way too low and honestly you'd really want to see about 120 for a healthy motor. I have seen 145, might be 165 around.

not firing at all? coils do happen, but it's rare in my shop. carbs and gas are usually the issue.

fresh mix a gallon with decent oil.

well, actually, if you have compression I might try hitting it with ether. just a blast or so and see if the saw tries to do anything. choke off and pull.

a lot of guys don't like ether because it can have a "washing" effect. it takes the oil off, so you don't want to go too crazy. but I have found a judicious blast or two is beneficial in diagnosing. if it tries to start it's fuel/carb. if it doesn't you have to try another way to rule out the coil.

pull the plug, plug it in the sleeve and ground the electrode against the head. make sure the switch is on and have someone pull it. you'll be able to see the spark in the sparkplug if it's working. you could try unplugging the switch if you don't have spark, but keep in mind that you'll have no way to kill it. take the chain off if you haven't if you try this. you can maybe choke it or spray carb cleaner in it to kill it. put your thumb over the carb and strangle it? if no spark doing all of that it's worth getting a coil or checking the gap at least. a business card will give you a "close enuf" coil gap. it's usually around .030 or so.

wock said:

how are you testing compression? start it from empty, 3 quick pulls and read it.

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This is a decent way to measure the ratio of the engine displacement to the volume of the gauge hose, but it's not a way to get a meaningful compression reading.

Jon1270 said:

This is a decent way to measure the ratio of the engine displacement to the volume of the gauge hose, but it's not a way to get a meaningful compression reading.

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how would you do it?

doing a leakdown test to verify it requires a probably close to $100 pump ($70 at my discount thru work.) that most homeowners aren't likely to have.

when you push the primer bulb it collapses... are the fuel lines reversed?

I'm not advocating a leak-down test. The problem is the "3 pulls" part of your direction. To get a reading that tells you about the condition of the seal between rings and cylinder, you need to keep pulling until the reading stops climbing and levels off. There is no fixed, correct number of pulls that it takes to do it, and using a small, fixed number will produce lower readings on small-displacement engines than on larger engines in similar condition.

Sean McGillicuddy said:

Hmmm I hadn't thought of that.
Doe some one have a diagram to help?

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not off hand, I just kind of work it out to be honest. switch the lines and see if the primer bulb acts more "normally".

something like fuel filter to line to outside primer. center primer to carb and carb back to fuel tank. 3rd line from fuel tank, if it has one is just a vent.

leave the fuel line in the tank to the filter pretty long so hopefully it reaches gas even on it's side. using a fuel filter is good because the weight will help keep the line on the bottom.

Jon1270 said:

I'm not advocating a leak-down test. The problem is the "3 pulls" part of your direction. To get a reading that tells you about the condition of the seal between rings and cylinder, you need to keep pulling until the reading stops climbing and levels off. There is no fixed, correct number of pulls that it takes to do it, and using a small, fixed number will produce lower readings on small-displacement engines than on larger engines in similar condition.

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that's kind of a "chicken and egg" argument. a compression test is mostly to give you an "idea" of what's going on. 3 is all you really need. who am I to second guess the people that make the gauge?

compression tests are inherently inaccurate anyway generally speaking.

wock said:

compression tests are inherently inaccurate anyway generally speaking.

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No argument there; the variation between gauges is often significant. However a given gauge should behave fairly consistently from engine to engine unless the check valve is recessed too far into the fitting that screws into the cylinder. The 'three pulls' idea needlessly discards much of the utility that the gauge is capable of providing. I doubt the instructions that came with your gauge said anything about "3 quick pulls."

I have come to the conclusion that for frequently used items you need high quality purpose specific tools. This doesn't mean you have to spend the most or get the absolute highest priced brand.

Life is just too short. I would rather not have the tool then have the job (or my time) ruined by a cheap one.