STIHL 031AV Chainsaw will not start.

[dirtyb115]

Hi all. I have a stihl 031AV chainsaw that quit running on me a couple of years ago. I bought a cheapy at home depot but would really like to get the 031 working again, loved that saw.

So basically, every once in a while when first try and start on full choke ill get it to fire just a bit, but it immediately dies. Then nothing no matter what i do. Most of the time it wont even fire at all. I tried a new plug first, then checked spark and it looked fine. I have cleaned the carb out several times, but the plug does get wet when trying to start it. I have also tried adding a tiny bit of fuel in the spark plug hole and still nothing.

I also tried removing the exhaust thinking it could be clogged, still nothing.

I dont have any way to do a pressure check but it seems to have good compression. I can pick it up be the pull rope and it slow goes down as it turns over. (Not the most scientific i know.)

Does anyone have any ideas? Since there is fuel and spark im guessing its low compression, but hoping maybe there is something else i can check..

 

[crash325]

I went through very similar with an 041 farm Boss. It is pretty old with lots of time on it.

I found the fuel line was collapsed. After replacing it there was and is still a problem. The only cure so far is to remove the air cleaner, set the choke & throttle, then pour a cap of gas into the carb. With that done it usually starts on the first pull. Open the choke in a few seconds and keep the engine speed up for a little while. Been using it that way for quite a while. Once warmed up and used a little it starts right back up.

Rebuilding the carb may be the real answer as I understand there is a starting circuit in it. Will try that next I get close to the Still store in town and pick up some parts.

hope that helps. :thumbsup:

Work the curse of the drinking class.:thumbsup::thumbsup:

 

[dirtyb115]

Thanks for the suggestions, tried everything but no go. I checked both lines on the carb and neither were cracked or bad. I also replaced fuel filter and made sure that line was okay.
Still no go. This thing just wont start.

 

[dirtyb115]

Well tried messing with the fuel screws and if i took both of them in almost all the way i could get it to fire. Almost started going a couple of times but still no go. Plug is getting plenty of fuel, its soaked everytime i take it out.

Guess ill try a compression check next. Will a cheap harbor freight one suffice?

 

[JakeBrake]

Hi all. I have a stihl 031AV chainsaw that quit running on me a couple of years ago. I bought a cheapy at home depot but would really like to get the 031 working again, loved that saw.

So basically, every once in a while when first try and start on full choke ill get it to fire just a bit, but it immediately dies. Then nothing no matter what i do. Most of the time it wont even fire at all. I tried a new plug first, then checked spark and it looked fine. I have cleaned the carb out several times, but the plug does get wet when trying to start it. I have also tried adding a tiny bit of fuel in the spark plug hole and still nothing.

I also tried removing the exhaust thinking it could be clogged, still nothing.

I dont have any way to do a pressure check but it seems to have good compression. I can pick it up be the pull rope and it slow goes down as it turns over. (Not the most scientific i know.)

Does anyone have any ideas? Since there is fuel and spark im guessing its low compression, but hoping maybe there is something else i can check..

My Stihl dealer, who was in business when the 031AV was in production, says he can not get critical parts for the 031AV. He said if he could get parts, he would make a fortune because there are a lot of them out there (including mine) that the owners would love to get going again.

 

[wrooster]

I have a stihl 031AV

go here,
http://www.arboristsite.com/chainsaw/
and search on 031AV for some background on your model, and also take a look around for general troubleshooting threads.
then post in this thread,
http://www.arboristsite.com/chainsaw/72322.htm
and request the FSM (factory service manual) and the IPL (illustrated parts list). these are the two documents you need. they will "appear" via links in your private message box; no need to thank anyone, they are doing you a favor in a pay-it-forward fashion.

hoping maybe there is something else i can check..

the symptoms you describe can be a lot of things. unfortunately some of them are internal. with an old saw i immediately suspect the following: impulse line, fuel line, fuel diaphragm, and main seals. if the main seals and or impulse line leak air the saw will never run right, much less start.


Regards,
wrooster

 

[V1Rotate]

I also have an 031 and love it.

Here's another idea. I know you said that the saw has spark, but sometimes if you have bad points and condenser you can get spark when you test it but the saw will not start (this can happen to all gas engines not just chainsaws).
The reason is that the high pressure inside the cylinder increases the resistance of the air gap of the spark plug. If the spark is a little bit weak, it might not be enough to fire the engine.

Just an idea.

 

[dirtyb115]

Well just did a quick compression test. Only 65 lbs so guessing thats way to low. I work on dirtbikes often, but not chainsaws. Do you think new rings would be enough if the cylinder walls are not bad? Do they make oversize pistons for these if not?

Maybe time for a new saw but i really did like this one.

 

[dirtyb115]

Well it all makes sense now . Took the cylinder off and you could see where a piece of metal made it past the rings and banged up the top of the cylinder a bit. I was hoping a ring broke or maybe the upper rod bearing but they all looked good. Then i noticed the bottom rod bearing did not look right. After closer inspection it has broken and Im guessing that is where the metal came from. So.... How hard is it to split the cases on this saw, and can i still get the lower rod bearing and any gaskets ill need? If i decide to do this, what other parts should i replace while im in there?

It would probably be smarter to buy a new saw but its this far apart already.....

 

[955Lincoln]

It would probably be smarter to buy a new saw but its this far apart already.....

Yes, I think you are right but I can relate to your attachment situation. I like the quality of older stuff and still use a 70's Homelite Super XL even though it's way too heavy. Luckly there are tons of these still around in basketcase condition if I should have a meltdown. Do a Google search and see if you can find new parts for your model or look on E-bay for a parts machine. If you work on dirtbikes splitting a saw won't be any problem.

You could also get a new saw and make this your backup so you can still have it around.