I have an OS .61 FX that I have running in a Graupner Showflyer. I have run the engine a total of maybe 10 times. It is on a MACS tuned pipe for that engine. The problem I am having is that it seems not to be pulling fuel into the carb. I can choke it, since the engine is mounted on a 45 drgree angle, the fuel will spill out of the carb. I can get it to fire, but it burns the choked fuel in it and dies. I have messed with the settings, rich an lean, takne the carb apart and made sure there were no foreign objects in it ( I landed in the grass once with it ) I am at a loss as to why this thing won't fire. I have changed glow plugs, everything. I am running 10% Nitro Fuel. Any opinions would be appreciated !!!