I have an OS91FX with stock muffler and needle valve which runs just fine... the only problem I have had with it is that I kept crashing the airplane it was attached to! [:@]

So like a fool, I went out and bought an OS .91 FX two stroke. I read some of the threads here on RCU about the metal remote needle with its fuel bubbling issue and its air leaks, so I THOUGHT if I found one with the composite remote needle, I would be ok... Stupid me for thinking that... Well as you can tell, I got a real stinker anyway. After 1 1/2 gallons of fuel, 4 weeks of available flying time, and A LOT LESS HAIR ON MY HEAD, I'm calling it quits with this OS Engine (OS must stand for Outright S**TTY) If I set the high end needle to max rpm and then go 3 to 4 clicks richer, (200 to 300 rmp loss) and then set the low end for best transition and idle quality, the midrange is soooo rich that if you throttle back and after a few seconds throttle up, This engines ALWAYS burbles, stumbles and dies. Yet another deadstick. In 4 weeks, I have yet to fly more than 5 laps on any given flight, and never without a deadstick. I have read the posts here about cures for the rich midrange, followed the advice of all of them, and even had several of our clubs best engine guys (Some of which are OS ONLY guys) and not one of them can make this POS run right. I will either return this thing to OS for an exchange on a different engine, or I will just dump it on ebay. (Yes I'll tell everyone in the listing all of this. (I believe in being honest)