RE: O.S 1.60FX Owners. Post your tach readings
Hitec,
I've got the same airplane, engine, prop and muffler as you. I'm at 3000 ft. and my airplane has unlimited vertical. I'm running Byron 15% nitro / 20% oil and my Mezjlik 18X6 is turning around 9000 rpm usable, peaking at 9300 rpm. Don't get your fingers into it else they'll be gone. Enjoy!!