QuestionI have a stihl 028WB chainsaw that sometimes idles but when
I try to accelerate it spits fuel out of the carburetor
throat, smokes heavily out the muffler, rarely reaches full
throttle (and then only for an instant) and then dies.
Sometimes it doesn't do that well and just tries to start.
I've replaced the fuel line, cleaned and rebuilt the
carburetor, tried adjusting the carburetor(it didn't help),
replaced the head gasket and replaced the spark plug (it
seemed to work better w/ the wrong plug). The muffler is
oily but clean, I've not replaced the fuel filter or the air
filter but I've tried to run it w/o them (no change),the
compression is 150 psi, and I'm using a 50:1 mix. Also I
would like to know where the best place is to get a stihl
woorkshop service manual for an 028WB chainsaw. I found one
@ tradebit.com that's "supposed" to be for almost every
stihl machine made before 2008, but I wonder if it's true.
Thank you for your help.
Answerhello Jared,
I myself am a stihl man! The first thing you need to find out is if its gatting spark? But from the sounds of it I would say that the intake valve is stuck! It might not be seating correctly,there is a valve seat that looks like a metal ring and if it popped out it would cause the intake valve to get stuck so the fuel would not get to the cylinder correctly!If you changed the head gasket,I would try pulling the head off again and with it off turn the motor over by hand. The piston should move in and or out as you turn it over.As you turn it over there are two valves,one is an intake from the carb,and the other is an exhaust valve. While turning it over by hand both of these valves should move in and out opposite one another.If you are not a handy person you probably want to find your nearest stihl dealer and bring it in for repair! I hope I answered your question,
Jason.....
....I got to thinking about your issue and wanted to let you know that it could have a keyway in the flywheel? I am not sure about that but if it does and it is worn or broken than the saw would be out of timing? If you want to check look where the flywheel is and there is a nut holding it on the motor.If you can see a square thing near the shaft about a quarter in by quarter inch.that is what hold the timing of it! If you cant see it you may have to take the big nut off,and it will be right on the shaft! If its broken you need to take the flywheel off with a puller! And replace the keyway! Cheap part,and if that's it you will have a good running saw again!
