# Chainsaw bogs down at high speed



## reaperman (Dec 28, 2007)

My stihl 044, saw is starting to bog down at full throttle. Its more pronounced when the saw is first started cold. After starting the saw I rev it up and down to warm it up. But when it hits wide open it bogs, so I feather the throttle to keep it going. When I start to cut it warms up and runs better. But as soon as it is rev'd wide open it loosed some power. If I back it off to 3/4 throttle, it rev's higher. I can feather it to wide open, but if I "crack it" and hold it wide open it can't catch up and I'll have to let it idle down and feather it to wide open. The saw runs great at a idle, and I can still cut, but full power is just not there.  I always use high octane gas with stihl oil. Maybe the high setting on the carb needs to be adjusted, I havent tried that because it has always run great since I had the saw (13 years). I didnt want to start messing with the carb adjustments until I came before the experts (thats you guys), first. 

One other note, I put a new piston in the saw about 4-5 years ago, the old piston for some reason just shattered. I dont think this has anything to do with the current problem. I've cut a lot of wood since replacing the piston.


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## windthrown (Dec 28, 2007)

Sounds like you are running out of torque! (ha ha)

You probably need to adjust the H setting screw on the carb. Turn it all the way in to seat it and then turn it out the number of turns marked on the side (if there are marks left, usually 3/4 or 1 full turn). If it it is not that it probably is a clog in the carb someplace or in the fuel line. 

My best guess anyway. You should be re-tuning the carb about once a year (at least) to get the best running idle, L and H settings. They tend to move around some over time and use. Also check that the carb is fully seated/bolted onto the manafold; sometimes you can get air leaks over if the gasket dries out or the nuts come loose (again over time and use).


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## ericjeeper (Dec 28, 2007)

*Get her warmed up*

Put it in a log running wide open and hit the kill switch.. Then pull the sparkplug., Compare it to a 3 year old carhart coat. If white richen it up a lot.. if black lean it out.


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## chainsaw kid (Dec 28, 2007)

*suck squeeze bang blow*

Did this problem come on all at once or did it gradually get to where it's at now?


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## reaperman (Dec 28, 2007)

chainsaw kid said:


> Did this problem come on all at once or did it gradually get to where it's at now?



I never noticed this last year. And I'm first starting to cut again now. So the saw has pretty much sat since last winter when I did the majority of my cutting. I'll try the carb adjustment mentioned in the first reply, I never knew what that 4/3 meant before. And I'm not to familiar with carbs to go screwing in the settings. I remember I couldnt believe how small the carb actually is when I took it out to replace that piston. Thanks for replies.


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## chainsaw kid (Dec 28, 2007)

So it sat for a wile.....Whens the last time you rebuilt the carb? You can and should try the carb adjustment but a fresh carb is nice.


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## Lakeside53 (Dec 28, 2007)

Sounds like you have an air leak... get or do a pressure and vac test.
I assume you've been changing your fuel filter now and then?


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## mountainlake (Dec 29, 2007)

Sitting for almost a year I'd clean the carb first and check lines for cracks. Don't use gas with ethonal and put Stabil or something like that for storing. Gas seems to get worse every year. Steve


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## chainsaw kid (Dec 29, 2007)

Lakeside53 said:


> Sounds like you have an air leak... get or do a pressure and vac test.
> I assume you've been changing your fuel filter now and then?



Andy, I thought a sign of an air leak would be the saw idleing weird or it taking off on it's own. I know you are a welth of knowledge, please explain...
I could see the filter as being a problem though.

Reaperman, How is the compression? Why did a piston shatter a few years back? How dose your muffler look...is it clean?


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## West Texas (Dec 29, 2007)

I just fixed an 026 with the same problem, started, ran, idled but would cough and die in the cut. After doing a compression, piston, cylinder, plug, and seal test, I pulled the carb and put in a new repair kit. Still a problem. Found junk in the gas tank;but,filter was OK. After screwing with that carb for far longer than it was worth, I put in a used carb that I had in the shop as a backup. Problem solved. My belief is there is some junk in that carb that normal cleaning, disassembly, blowing with air gun, replacement of parts, etc, did not solve. 

Now I'll take it apart one more time and soak it in carb cleaner overnight; put it back together and try it on one of my 026's and see if that has solved the problem. If not, toss it. My time, even as a retiree, eventually becomes more valuable than an old carb.


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## reaperman (Dec 29, 2007)

Update:

Windthrown was correct

I turned the high idle screw all the way in and backed it off one full turn and its running great.

Another question: The plug is on the white-side, so I'd like to richen it up a bit. The bottom adjustment has the letters LA which way do I turn that bottom screw to make it run a bit richer??


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## windthrown (Dec 29, 2007)

Well, I just love being RIGHT sometimes...

The LA screw is the idle set screw. Use that to adjust the idle speed. I set my idle to just where the chain stops running (clutch does not engage). That does not effect the mix though. 

To get a more rich mix turn the H screw OUT a tad more. Maybe 1/8 to 1/4 turn. Maybe richen up the L screw OUT a tad as well. That is a little harder to get right. I set the L screw for best idle and throttle response. More of a 'set by feel' than anything else. Usually a 0 to 1/4 turn more than the factory setting. 

If you want to err... err on the rich side. A lean mix can blow your engine in a hurry. Which has me wondering why they have limiter caps that can only be adjusted toward running lean... :monkey: censored: EPA)


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## reaperman (Dec 29, 2007)

Since it is running good now, maybe I'll cut for an afternoon and check the plug again. I only ran it for a couple of minutes after setting the idle screw.
It was turned out about 1 1/2 turns before taking the correct advice on how to set it. I just dont want it running too lean, and risk blowing another piston again. 

I'm not sure why the piston shattered on me a few years back. I was just limbing out a tree and the saw just quit. I tried to pull the rip-cord, and "no dice". The local stihl dealer ordered me a piston ($125). I had him look at the cylinder wall first and get his opinion, he said it looked good. But couldnt really give me a reason as why it happened. I put the piston in myself and took it back to him to fine tune it ($2, couldn't beat that). And it ran great ever since. 

I wish I could buy gas without ethnol, but Minnesota state law says 10% in every gallon. I normally dont use stabil, because when I mix up a gallon, its usually gone with in a week or so. Maybe I should start using seafoam or something anyway,for a cheap insurance policy. Thanks for the replies guys, its a helpless feeling when my baby's (044) sick. It very rarely happens but when it does its desperate times.


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## windthrown (Dec 29, 2007)

Yah, the corn lobby at work = 10% ethanol in gas. We are fortunate to have real gas available here, though a lot of it around here is 90/10, which is all they can get in the bigger cities. Never mind CA gas... ethanol is bad enough on seals and gaskets, MTBE was terrible, at first more or less mandated by CA air quality, then banned. They have mainly ethanol mix there now, but some stations out of the cities have all gas.


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## RiverRat2 (Dec 29, 2007)

*save this link to your favorites,, ITs a good one for adjusting carbs!!!!*



reaperman said:


> Since it is running good now, maybe I'll cut for an afternoon and check the plug again. I only ran it for a couple of minutes after setting the idle screw.
> It was turned out about 1 1/2 turns before taking the correct advice on how to set it. I just dont want it running too lean, and risk blowing another piston again.
> 
> I'm not sure why the piston shattered on me a few years back. I was just limbing out a tree and the saw just quit. I tried to pull the rip-cord, and "no dice". The local stihl dealer ordered me a piston ($125). I had him look at the cylinder wall first and get his opinion, he said it looked good. But couldnt really give me a reason as why it happened. I put the piston in myself and took it back to him to fine tune it ($2, couldn't beat that). And it ran great ever since.
> ...



http://web.archive.org/web/20051018212959/www.madsens1.com/sawtune.htm

Get some Stihl Ultra Pre mix its synthetic and it keeps your motor internals clean and extremely well lubricated,,,, It also has a stabilizer in it already,,,,

As for the crummy gas you could go to one of the local general aviation airports and get a couple of gallons of some 105 octane av-gas,,,, there wont be any alcohol in it,,,,,, 

River,,,


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## chainsaw kid (Dec 30, 2007)

*Rebuild the carb*

That's awesome you got it running good again by adjusting the carb! That's what I'd do first off. In my way of thinking, you did some troubleshooting. In the 13 years you'v had that saw, when is the last time you rebuilt the carb? If you haven't rebuilt it, use the saw a little and you'll see you probably like it. Then, buy a $10.00 carb rebuild kit and rebuild the carb, adj it again and I bet it will be outstanding and you'll love it  

Reason being is that parts inside the carb that come in that kit, are normal wear items that over time shrink/wear out therefore not optimizing your saws performance. Yes the h & s needles can/do move a tad with nml usage, but if you have to make drastic changes in a year....rebuild the carb and you won't have to worry about that potential problem.

Note: this is my logic and if I am wrong, someone please post saying so.
I'm always willing to learn.

Kevin


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## mountainlake (Dec 30, 2007)

chainsaw kid said:


> That's awesome you got it running good again by adjusting the carb! That's what I'd do first off. In my way of thinking, you did some troubleshooting. In the 13 years you'v had that saw, when is the last time you rebuilt the carb? If you haven't rebuilt it, use the saw a little and you'll see you probably like it. Then, buy a $10.00 carb rebuild kit and rebuild the carb, adj it again and I bet it will be outstanding and you'll love it
> 
> Reason being is that parts inside the carb that come in that kit, are normal wear items that over time shrink/wear out therefore not optimizing your saws performance. Yes the h & s needles can/do move a tad with nml usage, but if you have to make drastic changes in a year....rebuild the carb and you won't have to worry about that potential problem.
> 
> ...



I like your way of thinking, start with the simple stuff. Most likely when he turned the high adjuster all the way in it dislodged some crud and cleared it out. That adjuster didn't move from the time he stored it when it was running good to when he started it again. One turn out is a starting point for adjustment not the final setting, I turn the the low out a little more after carb work as it will start a lot faster. Steve


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## logbutcher (Dec 30, 2007)

*Yes*



RiverRat2 said:


> http://web.archive.org/web/20051018212959/www.madsens1.com/sawtune.htmRiver,,,



We needed that reminder -- I have a case of C.R.S. :censored: .....much thx RR . Now if the ear would work tuning..... 
We owe you.


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## reaperman (Dec 30, 2007)

I have never re-built the carb, nor have I really done any repairs since the beginning. It always seemed to run fine. I bought the saw used (less than 2 hrs) from a friend who thought he was going to cut wood for cash. But he found out cutting wood is work, and he is lazy. I had just purchased my propery (1993), 45 wooded acres, and he offered me the saw for $500. I had a olympic saw at the time and sold it to another friend. So I guess I've pretty much had it from the start.

I would be interested in re-building the carb, I have a stihl dealer within 2 miles of my place. Is that the best place to get the kit or online? One thing I did notice before I adjusted the carb, the saw took a few more pulls (maybe 10) to get it started form cold. After, 3-4. Would I need the serial number off the saw to get the correct carb kit or is there a # on the carb itself. I looked for the serial # and I think I found it next to the muffler, above the chain on the body of the saw, 125155675 . Does this look right? Also, would you recommend taking the saw to the dealer after I'm done cutting for the season for a general tune-up? Or maybe have it done now? I do have another saw a husky 137, a little #### I got free when I bought my woodsplitter. It actually cuts pretty well for a small saw, I have been cutting smaller stuff with that and the bigger logs with the 044. So I could just use the husky until mine was done with a tune-up if I had to.


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## Lakeside53 (Dec 30, 2007)

125? that's one of the early 044's... 

Best to take the carb type (ZAMA or WALBRO), and type. If your dealer sells you a Stihl kit, it's more expensive, but he may also sell aftermarket (many do). A full C3M Zama kit online is $5-7, plus shipping. Locally (around here they sell for $10-15).


Annual maintenance? - empty out the fuel tank, replace the fuel filter (use the NEW type large bodied Stihl), new plug. Grease the clutch bearing, check the drum, hoses, wires, boots etc..


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## chainsaw kid (Dec 30, 2007)

reaperman said:


> I have never re-built the carb, nor have I really done any repairs since the beginning. It always seemed to run fine. I bought the saw used (less than 2 hrs) from a friend who thought he was going to cut wood for cash. But he found out cutting wood is work, and he is lazy. I had just purchased my propery (1993), 45 wooded acres, and he offered me the saw for $500. I had a olympic saw at the time and sold it to another friend. So I guess I've pretty much had it from the start.
> 
> I would be interested in re-building the carb, I have a stihl dealer within 2 miles of my place. Is that the best place to get the kit or online? One thing I did notice before I adjusted the carb, the saw took a few more pulls (maybe 10) to get it started form cold. After, 3-4. Would I need the serial number off the saw to get the correct carb kit or is there a # on the carb itself. I looked for the serial # and I think I found it next to the muffler, above the chain on the body of the saw, 125155675 . Does this look right? Also, would you recommend taking the saw to the dealer after I'm done cutting for the season for a general tune-up? Or maybe have it done now? I do have another saw a husky 137, a little #### I got free when I bought my woodsplitter. It actually cuts pretty well for a small saw, I have been cutting smaller stuff with that and the bigger logs with the 044. So I could just use the husky until mine was done with a tune-up if I had to.



I would go over to the stihl dealer near you and buy a rebuild kit as long as it's between 10 and 20 dollars otherwise look elsewhere. Just take your carb off and get the # off it before you go or just take it with you for that matter. Also replace the fuel filter (like mentioned) and you might as well get the fuel line also because it will break when you mess with it to pull off your old fuel filter and you will be making another trip to the stihl dealer. Look at your air filter too...if it looks like crap, replace that as well. Change the plug. Take the covers (all you can) off the saw and clean all the built-up saw dust off everywhere you can. Take the clutch apart and grease the bearings (*don't go crazy with greasing the bearings because you don't want any to migrate out to the friction surface on your clutch drum*) Also, if that clutch drum has excessive entrenched wear marks from the chain....replace that also.

As far as rebuilding the carb....You'll have fun doing it....you just can't be hammer fingers and take your time. After you get it all back together, make your carb adjustments... get it running then bring it to your stihl dealer to do the final tweaking of the carb. Now you've done the tune-up with the care of someone who owns the saw plus saved yourself some money learned about it and had fun. 

Kevin


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## windthrown (Dec 30, 2007)

Yah, I would have to say that a carb rebuild is not an anual or even semi-anual thing. Being that our saws and other 2 stroke powered stuff are never idle around here for long, there is really no down time or anual time for needing to rebuild the carbs. Truing bars, changing sprockets, replacing gas and impulse lines, cleaning and replacing filters and debugging running issues takes up all my saw tuning time. Sharpening chains is where I spend most of my time on saws. 

That said, there is certainly a time for rebuilding carbs. I should rebuild the carb on the 210. But easier just to put on the one from the spare parts 250 after nipping off the H limiter. The 210 likes a 7/8 turn instead of the factory 3/4 with a poor-mans instant screwdriver muffler mod (simply bend the muffler fins open more).


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## 820wards (Dec 30, 2007)

windthrown said:


> Sounds like you are running out of torque! (ha ha)
> 
> You probably need to adjust the H setting screw on the carb. Turn it all the way in to seat it and then turn it out the number of turns marked on the side (if there are marks left, usually 3/4 or 1 full turn). If it it is not that it probably is a clog in the carb someplace or in the fuel line.
> 
> My best guess anyway. You should be re-tuning the carb about once a year (at least) to get the best running idle, L and H settings. They tend to move around some over time and use. Also check that the carb is fully seated/bolted onto the manafold; sometimes you can get air leaks over if the gasket dries out or the nuts come loose (again over time and use).



I agree with WINDTHROWN,

Sounds like a combination of your High/Low screws could need adjustment. I also had a problem with the inline filter in a tank getting dirty from wood dust, thus, starving the carb at high RPM under load. You may even need to remove the the fuel pump diaphragm on the carb and clean the tiny filter that feeds into the carb. Real fine particles of wood dust can clog the screen causing idle and fast speed running. A vacuum leak would make the motor start and die, start and die. 

Don't know how old your saw is but, I had a problem with my 8.2c.i. PowerBee motor actually collapsing the fuel line because the filter was plugging up from crud in the tank. I learned my lesson to never loan my saws to my little brother.... 

jerry-


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## chainsaw kid (Dec 30, 2007)

820wards said:


> I agree with WINDTHROWN,
> 
> Sounds like a combination of your High/Low screws could need adjustment. I also had a problem with the inline filter in a tank getting dirty from wood dust, thus, starving the carb at high RPM under load. You may even need to remove the the fuel pump diaphragm on the carb and clean the tiny filter that feeds into the carb. Real fine particles of wood dust can clog the screen causing idle and fast speed running. A vacuum leak would make the motor start and die, start and die.
> 
> ...




Yeah, I agree with windthrow too.

If a saw is used all the time then yes....the internals of the carb will last a long time. But, if you are going to take the carb that far apart, why not spend $10.00 on a rebuild kit and have a fresh carb. Especially if you have a saw that sits idle for months at a time each year. Windthrow uses his saws all the time and if worked those carbs would be fine.


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