Chainsaw low power at full throttle?

Question

I have a gas chainsaw that acts funny when I put the throttle on full. It sputters and has very low power. If I let go of the throttle and have about 75% throttle, it runs much better (but not perfect). What would cause this?

Answer 1

Your air cleaner is dirty.  The more gas you apply, the worse the fuel-air mixture becomes until it is so rich it cannot combust properly.  Easily check this by removing it, then replace or clean if so.

Answer 2

Clean/ or replace air filter, change spark plug ,

Answer 3

Carburetor out of adjustment or gas filter dirty(the small one in the carb.

Answer 4

Before you tear into the carb, check the fuel line from the tank, and then check the spark arrester screen.  The holes in the fuel line will cause the fuel to air mixture to suck more air lowering the power of the saw.  With the spark arrester screen in the muffler, if its blocked, will not allow the exhaust gasses to leave the cylinder which in turn will not allow fresh fuel into the cylinder.  This will cause the engine to bog down and under preform.

Answer 5

Try adjusting the high speed jet in the carburetor.  If that doesn't help check the air and fuel filters.  chances are the carburetor needs to be rebuilt.  The kit is about $15.00 and it is an easy job.