# Stihl Chainsaw Repair - Stalling at Full Throttle



## Gemo

I have an Stihl (model 009) several yrs old which has given me good service, however now it is giving me a problem.

It starts and runs well - except when operating at full throttle (ie. cutting wood) it starts to stall as though running short of gas. If you back off or 'feather' the throttle it'll pick up speed again for 5 seconds and then start to stall again ... etc.

It seems like it's not geting enough gas at full throttle so a fuel blockage or carb problem is at fault. I've cleaned out the gas tank, changed the fuel pick up filter in the tank, checked the fuel line, checked and cleaned (including dissasembly and blowing out all the holes...) the carb 6 times...

All the carb parts seems good including gaskets and diaphrams. The one part I haven't checked or changed is the fuel jet (not sure how to remove it from the carb body) although I blew high pressure air through it and it seems to be clear...

The symptoms sure seem to be fuel/carb related but I've tried eveything I can think off - sure hope someone can help.


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## justin3

Have you adjusted the carb mixture screws? Turn the high mixture screw counter clockwise 1/4 of a turn and see if it makes a diff.


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## Gemo

Thanks for the question.

Yes I have adjusted the mixture screws and they adjust just as you would expect - eg. for high speed you get a nice tuning at full throttle but as mentioned when you run the saw for ~10 seconds at full speed it starts to slow/sputter as though it is running low on gas.


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## dough01

I have a Stihl model 028 that just had a somewhat similar problem. 

I noticed that actuator bar between the throttle trigger and the carburetor wobbled when I pulled the trigger. Turns out the plastic top on the handle had come loose and was no longer properly installed and in coming loose, it let the actuator bar come off the trigger. But, the bar was still in tenuous contact with the trigger and was being pushed, but the throttle could not open properly. As soon as I reattached the lever to the trigger, it ran fine at all speeds.


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## Gemo

Appreciate the suggestion but the linkage is solid.

Still need to do some more final testing but looks like I've fixed my problem. Even though all the diaphrams etc in the carb looked good I replaced them all with a 'carb kit' (only cost ~$10) and now the saw is running well at full speed.


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## lateena

*Stalling at full throttle*

Gemo

I had the same fault and tryed everything like you.
But it turned out to be the coil assembly so I replaced it with a solid state module and now I can honistly say it has never run better.Starts first pull early every time.
Cost me $130.00 Australian dollars.:thumbsup:

Lateen


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## luckyvision

very common problem, easy solution (usually) pull the exhaust screen, see if it's choked with carbon, if so, burn it in a propane torch, brush the carbon off or tap it & reinstall.

--Lucky


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## gr8horn

*Burning off the oil and cleaning screen*

It Fixed my problem! Thanks for the post!:dude:


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## W Glynn P

I have Stihl ms291 that has no compression it's not but 4 years old I was wondering if there is a good after marker complete power head available.TIA


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## Wazza65

Gemo said:


> I have an Stihl (model 009) several yrs old which has given me good service, however now it is giving me a problem.
> 
> It starts and runs well - except when operating at full throttle (ie. cutting wood) it starts to stall as though running short of gas. If you back off or 'feather' the throttle it'll pick up speed again for 5 seconds and then start to stall again ... etc.
> 
> It seems like it's not geting enough gas at full throttle so a fuel blockage or carb problem is at fault. I've cleaned out the gas tank, changed the fuel pick up filter in the tank, checked the fuel line, checked and cleaned (including dissasembly and blowing out all the holes...) the carb 6 times...
> 
> All the carb parts seems good including gaskets and diaphrams. The one part I haven't checked or changed is the fuel jet (not sure how to remove it from the carb body) although I blew high pressure air through it and it seems to be clear...
> 
> The symptoms sure seem to be fuel/carb related but I've tried eveything I can think off - sure hope someone can help.


I would without doubt tune the Carburetor, that sounds like the high & low speed mixture screws need adjusting. Definitely the simplest thing to try. If that fails you will most likely have to dig around in the Carburetor.


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