I think most running problems with the YS 4-strokes are owners not being experienced
enough with the engine to adjust it properly. I had all kind of problems getting mine to
run right and almost lost my pattern airplane because of a deadstick low and downwind
at a contest last year. I was sure cursing that engine until Earl Haury helped me adjust
it properly and it's run perfectly ever since. I haven't even touched the needle valve in
over a year and I don't think any 2-stroke is even close in torque and power. If you are
having problems with the YS ask for help from someone who is not having the same problems.

tommy s