Chainsaw bogs down at high speed

[chainsaw kid]

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

 

[windthrown]

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).

 

[820wards]

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-

 

[chainsaw kid]

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-

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.