# Chainsaw won't start when hot



## Tony Pip (Apr 26, 2005)

My McCulloch chain saw starts great cold, but after the first tank of gas it won't restart. If I take clean the plug it starts (sometime). It's a new plug gapped at .025".

Any suggestions?

Thanks


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## bugman (Aug 12, 2004)

is the plug nice and dry, usually a nice tan color thats nicely dry. also was it the right plug, some have a longer reach then others, some have less of a reach.


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## hankster (Jan 1, 1998)

What is the compression of the engine? Hard starting when hot can mean the engine is running too lean or the compression is low.


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## bhamct (May 1, 2005)

What should be the compression of most 2-cyckle engines or does it vary a lot from brand to brand?


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## hankster (Jan 1, 1998)

Chainsaws should be over 100psi, others like weedeaters and blowers can be as low as 90psi.


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## AbnMec (May 4, 2005)

*Won't start when hot.....*

It has been my experiencethat if an engine wont start when hot that you may have bad crankshaft seals. A quick test for this is to get the engine nice and warm...2-5 min. From the upright position at idle, turn the saw on its side... if the RPM's go up you have bad seals. The saw is allowing air to flow directly into the crankcase effectivley causing a "lean-out" and will ultimately cause piston/cyl damage.


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## em17976 (Sep 5, 2005)

I have just joined because after 3 recent (two weeks or less) 20" Craftsman(Poulan) chainsaws after a few minutes of running they would not restart. I felt like it was my wife's doing as she was waiting with the insurance policy.

I got tired of going to Sears for a gracious exchange. Finally, I found this site and discovered after much reading a common thread. Somebody said change the oil/gas mixture from 40:1 to more oil. I think I have it at 20:1. Also they said change the H carb adjustment 1/4 turn out.
I am now polluting the environment but IT WORKS. Darn 3 pulls at the most with a hot engine. Actually it doesn't get as hot as it was getting before the changes. It seems to run faster and NO HEART ATTACK. Sorry wife.
Thanks to everyone.


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## bugman (Aug 12, 2004)

actually 40:1 is good... try 32:1 or halfway from 40:1 to 32:1...it'll clog the spark arrestor up really quick, so i'd just remove it..... i got my little featherlite at a slightly more then 40:1 on synthetic weeder oil mix, carb adjusted so it slightly smokes at idle and full throttle... starts first pull cold most of the time, and first pull hot..... and i don't go easy on it.... i keep it as my backup. about 5 years old, today all they do is set em lean to pass the epa......


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## paulr44 (Oct 14, 2008)

Could be any number of things. Without more diagnostic info., I venture a guess at a hardened carb. metering diaphragm.


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