To All the chainsaw Wizards. Last summer I picked up a Stihl 025 from a yard sale and went to start it last week. The saw will start and run, however very high speed (seems like an air leak to me) sprayed carburetor cleaner around the clutch side,intake boot,carburetor , practically all over the saw with no change on the high speed. Also checked the piston for scoring which there was none. What am I missing here.
You mean high speed at idle? Good troubleshooting start. Have you tried to turn the idle down on the carb, if that’s where it’s running fast? Counter clockwise.
One way I check for air leaks, take an old inner tube and cut pieces of rubber big enough to block behind the carb and behind the muffler. Then I converted an air hose nipple and an old broken plug. Apply some(light) pressure and spray soapy water, look for bubbles (make sure the piston is below ports).
changing the carburetor does not change the high speed idle. i did not want to run it very much, afraid of a lean seize