Is your air filter on? This may sound silly, but I had the same problem when I first started mine and couldn't figure out why. I thought it was the clutch spring...NOPE, tried adjusting the idle scerw...STALLED. I was ready to throw it in the trash, but then (for some strange reason) I put the air filter back on, and guess what... All was good!! The only thing I could think of was that it was getting too much air and running rich causing this to happen. Could this be his problem??