Stihl 034 won't idle

[elscorch]

Ok just bought a 034 from a member on the site. He said it ran and cut well. I received it in good condition, started right up. Then after I revved it at WOT and released trigger it just died and was near impossible to start again. I thought it could be from the saw being run by the previous owner at sea level, i'm at 7000 feet. leaned up the low idle screw, nothing. richened it up, nothing. it seems to be flooding, and that's why it won't restart... I can start it up first couple of pulls after letting it sit for the night and it will run at full throttle, then just dies at idle. where to start? I was told it might need a high altitude valve jet, where can i get one?

 

[old-cat]

FIRST, make sure the impulse line is good, probably is but check it anyway. Then take the carb apart, check the metering diaphram and the pump side too. Make sure the metering valve lever in adjusted right.

 

[elscorch]

How do you know if the valve lever is adjusted right? There was a lot of grit on the diaphragms and in the filter too, but didn't seem like enough to block fuel flow... Impulse line looked good and I'll replace it. Why would it flood after wot? Tank vent seems good. Not sure what else, guess I'll buy a carb rebuild kit, or should I just get a new one from weedeaterman go $20?

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[elscorch]

OK carb is clean and back together, new impulse line on, just got to put it all back together and see if that fixed anything..

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[elscorch]

no luck, same symptoms as before, what now? I don't even know what carb I have it says tillotson, but it doesn't match up with any of the carb rebuild kits...

 

[old-cat]

I'm still learning myself about these 2 cycle carbs. I have learned that the lever adjustment is super critical, even a few thousanths can make a big difference. Flooding would indicate that the needle is opening too far.

 

[sefh3]

Well I hate to say it but pull the muffler and look at the piston. While pulling the muffler see if it's full of mix. If so it is too rich. What does the spark plug look like color wise?

 

[elscorch]

Piston looks pretty good and no mix in the muffler, lots of carbon though. Spark plug was wet last time I looked. I cleaned out the carb by taking it apart and cleaning diaphragms in mineral spirits. Readjusted lever, but I think it needs a carb kit, just don't know which one as this doesn't seem to be original. I'm thinking air leak somewhere...


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[Rockjock]

Piston looks pretty good and no mix in the muffler, lots of carbon though. Spark plug was wet last time I looked. I cleaned out the carb by taking it apart and cleaning diaphragms in mineral spirits. Readjusted lever, but I think it needs a carb kit, just don't know which one as this doesn't seem to be original. I'm thinking air leak somewhere...


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I have found after I clean the diaphragms I let them sit for a bit in WD40 and that seems to help. I found this out quite by accident when an old gasket was stuck to a carb body, my dad said spray it with WD40 and it will loosen up.. did that came back 15 mins later and it all looked really good thought why not try and run it. 2 years on still running strong.

 

[old-cat]

Please explain, readjusted lever. I seriously doubt a new kit will do any different unless the diaphram is stiff or something. It sure don't sound like you have air leak. If you want to replace the carb, the place I go is Chainsawr.com, their used carbs are usully about $35 and they have always worked fine for me.

 

[Wood Doctor]

Agree with Old-Cat. New carb kits do not always work. New carbs or used ones that work usually always work. You can still get new carbs for the 034. No such luck with the the old 041 and a few other relics.

Regardless, this trouble sounds like it could be the fuel line or the pickup body if the engine starts and runs for awhile. I usually start by checking those first before I move onto the carb. I once had a bad kink in a fuel line that produced similar results. When it sat for awhile, the fuel line would stiffen up and allow fuel into the line for WOT, but at idle speed, the carb could not pull it through. A clogged pick-up body can do the same thing. Both are cheap fixes.

 

[elscorch]

OK good to know, I'll check the fuel line next. I did just check compression and it's 125psi. I was told it was 160+...:-(

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[Big_Wood]

If what your saying makes sense to me it sounds like your high speed is to rich. When the saw goes back to idle it still has some left over excess fuel which kills it when the throttle butterfly closes cause there ain't enough air to keep it running. If that ain't it, it most likely is your metering lever set to high.

 

[Big_Wood]

OK good to know, I'll check the fuel line next. I did just check compression and it's 125psi. I was told it was 160+...:-(

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Wow. That member seemed to have stiffed you if your comp tester is reading correct. 125psi is low and definitely could be why it don't want to idle. I do have an urge to argue with your tester though.

 

[Big_Wood]

Delete double post

 

[elscorch]

Well I'd like to argue with it too! It was brand new out of the box, it held steady, no leaks... The seller seems honest, I'll give him the benefit of the doubt and give him a chance to fix it before I lay judgement. I'll probably go rent another tester to be sure...

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[elscorch]

Replaced carb kit, impulse line, rings and fuel line. Started up but flooded out again.. Took carb apart again, readjusted metering lever and it now purrs like an angry lion. Idles good too!

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[Wood Doctor]

Fixed. Congratulations! I was ready to buy the saw from you. But, I figured you would turn me down if I offered $200 cash.

Looks like a new carb altogether would have solved the problem. This is a good saw. Now, use it.

 

[elscorch]

Yeah, thanks for the help.

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[Adirondackstihl]

Just curious, what brand comp tester do you have?