My stihl 026 runs fine until its under a load "cutting wood" and it wants to die,I changed the plug ?

Question

the saw will start fine and idle fine untill it gets into cutting wood then it wants to die.

Answer 1

how sharp is the chain? also is the oilier working? and or is their a lube point at the end of the bar? As some take grease at this fitting, using a special tool. also may need to adjust the high speed jet to the carb. Check your owners manual.

Answer 2

One of 3 things, the fuel line is sucking air, the boot or impulse hose between the carb and cylinder is leaking, or the crankcase seals are going bad.  My bet would be on the boot or impulse hose.  Hoad the same thing happen to a saw that came in here today, and the boot was the problem.  A dealer can do a quick couple of test to find the problem.

Answer 3

My guess would be an air leak in the system. Start the saw and spray some carburetor cleaner behind the carburetor around the crankshaft and around the base of the cylinder. If it goes dead there is your air leak. Replace the bad gasket or seal.

Answer 4

If you check the fuel line that is in the gas tank you will find it has a screen filter on it. Clean this filter or take it off the gas hose either or.