A neighbor gave me a chainsaw to fix. He does lawn care and landscaping so I'm assuming it was used a decent amount. I think it just sat through the winter and then wouldn't start.

I gave 5-10 yanks, and it fired right up. Shut it off, tried to start it again and it started and died. Now I don't get anything. Pretty sure it's getting gas, the plug comes out wet and sometimes after pulling for a while some will dump out of the cylinder when I turn it upside down. It has spark, maybe a little weak, not sure, so that's my main guess, but no idea what is causing it. Everything looks OK. Pretty sure its not compression because it did start that one time, and I took off the muffler and didn't see any scoring.

Any ideas or advice? Thanks!

  • 1
    I know this isn't the right page, but I'm gonna say it probably needs a new carburetor. The ignition systems are generally very reliable on small engines. The carbs get affected by ethanol gas and rubber bits swell or become non-functional. Also, if unused for a while without a fuel stabilizer can cause problems. Best to use non-ethanol gas if you can find it. Lastly, the good news is carbs for small engines aren't that expensive....maybe $30-$40. I've had to replace a few on my yard equipment and cured the problems right away.
    – George Anderson
    Apr 27 at 18:36
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    Would get new spark plug first. Sometimes they will spark outside engine, but not inside. My ATV did that, new spark plug and started right up. Carb might just need cleaning or screws tighten up.
    – crip659
    Apr 27 at 18:43
  • @GeorgeAnderson Id normally agree with you, Ive replaced a carb in my string trimmer before for $10, and cleaned another. It does seem like thats usually the problem with them. But why is it flooding then? Shouldnt it at least fire once in a while, enough to keep it dry?
    – Randomaker
    Apr 27 at 18:48
  • I think it is the carb that does not keep the right fuel-gas ratio.
    – r13
    Apr 27 at 19:43
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    With the cylinder flooding I would go for the carb. Check the fuel float if that is stuck open it will flood the the motor even with a good carb, other than the float / valve. Mixed gas is bad for gumming things up.
    – Ed Beal
    Apr 27 at 20:12

In your situation, the most common cause is gasoline which has deteriorated and is blocking lines, pump, carburetor or other parts of the fuel system. Just having a wet spark plug does not assure proper mixing and atomization of the fuel.

The normal fix is to drain the fuel system, replace the fuel, and "rebuild" the carburetor, which is a cleaning and replacement of diaphrams, valves, etc.

The next likely cause is possible loss of timing alignment. If there was no trauma to the saw's motor, this is unlikely. However if it happened, you could still get spark without combustion.

  • I got it somewhat running yesterday, I think it's a mix of the low-speed jet being a little clogged, needing adjusting, and too low idle, so I shouldn't have any problems fixing it. Thanks!
    – Randomaker
    Apr 29 at 12:32
  • If the gas is gelled up, it can be possible that you will get it running, or partially running. If so keep it running, and the gel will get worked out. But often it will be something like a clogged idle port but it runs at higher throttle settings. If you have it running, even intermittently, you have lowered the odds which it is timing related. That's good.
    – mongo
    Apr 29 at 17:49

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