Originally Posted by
Tom M King
My first guess would be the spark arrester screen. Been running the Stihl oil in orange bottles?
The spark arrester screen is right inside the exit hole in the muffler. It's held in with one screw. Take that screw out, and slide the little screen out. If you can't see through it very well when held up to the light because of black gunk, that's your problem.
To clean it, hold it with some junk needle nose pliers, and heat it to red hot with a propane torch. Let it cool, and wearing an old glove, use you fingers sliding back and forth over it to release all the ash. It should now be clear like a new screen.
Put it back in, and it should run like a new one.
The orange bottle dino oil is terrible for clogging these screens. I haven't had this trouble since switching all my small equipment to the synthetic oil in silver bottles.
Originally Posted by
Dom Garafalo
I've had the same symptoms with both my Stihl chain saw and Echo grass trimmer and it turned out to be a clogged spark arrester.
There's a good chance that's your problem. It is a simple fix. Take off the muffler, which will expose the spark arrester which is simply a small metal screen with very small openings which become filled with carbon. You can either toss the spark arrester or clean the screen and put it back in.
You should check to see if you have a clogged spark arrester before spending any money on other parts or small engine service. This problem is well known with shops that fix and service small 2 cycle engines.
Good luck
Dom
I'd check there first.
Jim Bell
One more pass and you may see brass!