The Forestry Forum

Have a Stihl 441 that starts and idles fine and even start cutting.  But soon loses power and bogs down.  It has a new spark plug, clean air filter, new non ethanol gas.  I has a newly rebuilt piston from the dealer.  I sprayed it with carborator cleaner.  Any suggestions greatly appreaciated?

 Quit running it or you'll be putting in another new piston. Sounds like it's getting lean

 clogged carb. bad fuel line , maybe pinched
 clogged fuel filter
 clogged tank vent
 air leak
   a few things that could be wrong    Steve

Fuel mix vs tune; they must match. That said, don't just put more oil in the fuel because you are concerned about lubrication. Yes, you can do it, but if you don't retune the carb to match the fuel then ultimately the piston, cylinder and rings will pay the price. Remember, oil changes the viscosity the fuel going through the carb and by doing so then if you have more oil mixed with the fuel then the mix will not flow as readily, therefore you'll be running lean. READJUST or retune the carb to match your mix.

Thanks for the tips! could you suggest how to correct the clogged tank vent ?

Spark arrestor-check! Also the obvious;make sure you air filter is clean. 8)


Kevin