I have a sceadu 30 with a os 37 engine in it. The engine has had about 15 flights on it. The last few days I have noticed that its overheating and the smoke quantity has reduced a lot as well....so I richened it on the high speed needle. There is no real effect on the performance. Even with 6 turns out, the engine is overheating, and bogging down like crazy. The low speed needle seems fine, as the transition is really good. However, I have richened that considerably as well...went up to 1-2 turns. Seems like the needles are not making a difference to the mixture. The engine is smoking hot when I shut it down. What could be happening? I am using 20% nitro fuel with 20% oil.

thanks in advance

Check all engine screws and glow plug for tightness. Fuel restriction or air leak in plumbing or motor

Yep I agree Chris, I bet the plumbing is leaking and or the muffler pressure nipple is stopped up or the carb is not set tightly down on the O ring. Ya got air matey!!!

Jim

also make sure you do not have the needles set to lean.