I have the ST 75. I had two mufflers go on me, same thing, inside baffle came loose and it rattled like a bell. I took the thing off and finally put a tuned pipe on it. So far, so good. The carb leaks fuel out the needle valve.

I prefer OS. I have 2 46's, one 50, one 61, one 90, and three 1.20's. All are just fine start right up and run good with great power. NO fuel leaks and no muffler rattles.

DS.