I also used a zip tie on the idle disc - kept moving on my 1.8 (Bisson Pitts muffler, Menz 18x10). The engine ran great but had a noisy rattle sound at mid throttle settings. My Supetigre 3250 had a similar noise but was much less power/reliability. I sold 'em both and got 4-strokes. The rattle was/is a 2 stroke intake/exhaust note phenomena and is normal. Anyone else ever hear it?