stihl 031 and 040

[dockalmbach]

I have 2 saws that are old but work great for a short period.  You can use both of them for about one tank of gas and then they both do the same thing.  They get hot and start to pop and then die.  You cannot start them at this point.  They don't seem to fire. Pull till your arm gets tired and no start.  Let them cool down for about one hour then they will start again.  Same thing over and over again.  between the two you can get a little work done but quite annoying.  They both idle, run and cut like a champ while they run.  Any suggestions?  Any help would be appreciated.

[tyb525]

The might get vapor-locked as the gas is used up.

[blackoak]

I have 2 saws that are old but work great for a short period.  You can use both of them for about one tank of gas and then they both do the same thing.  They get hot and start to pop and then die.  You cannot start them at this point.  They don't seem to fire. Pull till your arm gets tired and no start.  Let them cool down for about one hour then they will start again.  Same thing over and over again.  between the two you can get a little work done but quite annoying.  They both idle, run and cut like a champ while they run.  Any suggestions?  Any help would be appreciated.

If your lucky it could be the condensers, if not, ignition coil and  they are no longer available from stihl. You can still get the condensers from Stihl.

[Troutfisher]

sounds like it may be ignition. next time one quits check to see if you've lost spark. if it's still firing then maybe a little  quirt of fuel into the carb....that would start it if it vapor locked or otherwise lost fuel. hopefully you can figure out if the problem's fuel or spark and go from there.

[Cut4fun]

I took a 031 on trade once that ran great for about half hour. Then it would cut out also and you would have to let it cool down before use again.
Turned out to be a condenser on that one. Good Luck.

[Al_Smith]

 Generally speaking regarding a breaker type ignition system the condenser will cause the most problems . It's made of oil impregnated paper wrapped between two conducting foils .As it ages and dries out  when it heats up,it fails . Then like magic works again once it cools off .

Those things have caused many an obscene word to be muttered .

Other than that usually a breaker type ignition ,if set correctly works pretty well .

[sgtme]

Had a Husky that did same thing took it to a repair shop, mechanic said it was just way out of adjustment, tuned and tweeked it a little, been good since then, mechanic did say that if the gas tank vent gets plugged it will cause similiar problems. Has anybody had issues with ethanol, alot of talk about it causing problems, just wondering if it is local or nationwide.