Outdoor Power Equipment and Small Engines - Stihl 021 chainsaw will not rev

Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.




View Full Version : Stihl 021 chainsaw will not rev


cftuna
06-28-06, 12:08 PM
I have a Stihl 021 chainsaw that ran good last winter. It now will start and idle but not rev up for power. There is not a high mixture screw. I have cleaned the carburator and it is fine with good seals, gas is new and mixed correctly, filters are clean, spark plug is new, chain is free and brake is off. What now it starts fine and idles ok just will not rev up past half throttle. :wall:


repair_guy
06-28-06, 12:47 PM
I have a Stihl 021 chainsaw that ran good last winter. It now will start and idle but not rev up for power.:

:blah:
Since it's been setting up for that long check the muffler/exhoust ports.Mud dobbers can reak havoc on a 2 cycle engine.

lexmarks567
06-28-06, 12:55 PM
how tight is the chain a too tight of a chain and the engine can't turn it.

I have a Stihl 021 chainsaw that ran good last winter. It now will start and idle but not rev up for power. There is not a high mixture screw. I have cleaned the carburator and it is fine with good seals, gas is new and mixed correctly, filters are clean, spark plug is new, chain is free and brake is off. What now it starts fine and idles ok just will not rev up past half throttle. :wall:


cftuna
06-28-06, 02:06 PM
Thank you gentlemen
The chain is lose enough to spin by hand
No blocked ports as I have pulled muffler and cleaned
I did find crack in fuel line and replace it.
Saw starts easy and runs to about 1/3 throttle then will not rev up from there......???:wall: :wall:

geogrubb
06-28-06, 04:15 PM
If everything seems fine I would check the throttle linkage to see that when you press the trigger it goes to full throttle. Have a nice day. Geo

cheese
06-28-06, 11:39 PM
What does it do, go up part throttle and hold there, or does it try to die when you pass 1/2 throttle? For now, it sounds like you still have a carb problem.

mikesmalleng
06-29-06, 12:30 AM
Check the impulse hole behind the carburetor to make sure that it`s not partially blocked by a misaligned or damaged intake gasket.
if not check for blockage behind the fiber insulator (behind the carb) The impulse hole must be completely clear in order for the carb, to be pumped properly.
Is your throttle cable stretched out?
Is the fuel filter disconnected from the fuel line inside the tank?