034 low idle jet

[1 stihl nut]

I've got an 034 that runs and operates marvelously. However lately the idle jet keeps getting out of tune. I can tune it, which requires an 1/8 turn more or less, but it goes out of tune after a short while. It seems it can go either way.... richer or leaner. I'm assuming it's turning on its own. What might a solution be? Isn't there a spring to tension it to give friction on threads? Is a careful application of blue loctite on the threads a possible solution. I can check that spring closer to see if it's broke...

Is this an issue someone has run into before?

 

[huskihl]

Couple things to try. You could put a drop of blue Loctite on the jet and let it sit for a day and then reinstall it. Or you could also install it while it was still wet and see if that worked OK. Another thing you could try is a small O-ring and washer that the needle spring could ride on and that may tighten it up enough to hold it in place

 

[1 stihl nut]

Couple things to try. You could put a drop of blue Loctite on the jet and let it sit for a day and then reinstall it. Or you could also install it while it was still wet and see if that worked OK. Another thing you could try is a small O-ring and washer that the needle spring could ride on and that may tighten it up enough to hold it in place

Thanks for reply. I never thought of letting loctite dry a bit first. Seems safer and worth a try. I'll examine the o ring thing when I get a chance to look at it again. Thanks again.

 

[drf256]

Is the screw actually turning position, or are you just assuming it is?

Pretty typical story for an air leak. Could still be the carb, but air leaks typically make you nuts chasing the right idle tune.

 

[1 stihl nut]

Is the screw actually turning position, or are you just assuming it is?

Pretty typical story for an air leak. Could still be the carb, but air leaks typically make you nuts chasing the right idle tune.

I usually first suspect air leak with tuning issues, but this tunes well and easy, but just doesn't hold it after a little cutting. Essentially just doesn't stay running at idle, until I adjust. I tied to look if screw had moved but was hard to tell as it's so little. I will check into this more though as part of diagnosis.

 

[pbillyi69]

can you make a mark on the screw and something else after you adjust it to see if it has moved maybe with a scribe or fine point sharpie

 

[Partner]

In old chainsaws, there may also be play in the carburetor throttle