OS .37 Overheating

[ptautor]

Guys,
I have a TT Raptor 30 with a OS .37 engine and a century tuned pipe I have been flying for a couple of months now, without a problem, and just the other day i was flying no problem when it slowly started losing power. I bought it down straight away. I tried touching the back of the engine and it was extremely hot. I figured this was the problem and it had overheated. I replaced the fuel, glo plug, checked the lines, clunk etc. and everything was fine. I richened it up a few clicks where i had to open up the throttle a little bit to keep it running. I tried hovering it for a couple of minutes, didn't have a problem, was plenty of smoke from the muffler. I bought it down and touched the back of the engine and again it was very very hot!

Im using 20% castor, 15% nitro, 65% methanol. When i take off the muffler and look at the piston, the top of it is brown. There is also some brown residue coming out of the muffler.

if anyone could shed some light on this it would be much appreciated!!

thanks!

[DavidH]

Castor oil no good for heli engines. Especially 20% Castor oil. Most of the major fuel manufactuers today, all the oil in heli fuel is Synthenic. Even the Castor/Synthenic blend oil packages. There is only a trace of Castor in those fuels.
Castor is the reason the top of the piston is brown and it will definitely gum up the engine.
That is probably what is causing your overheating problem.

David

[ptautor]

Thanks David.

I haven't been using the castor mix for long. Maybe only a few litres of that fuel through the engine. I didn't think that it would gum up that quick? I am working on getting a synthetic oil. Where exactly would it be gummed up, and how can i fix it?

Also i took the head off last night and bugger me there is no gasket to be found? Could this also be contributing to the problem? The engine was brand new and the manual says there should be a gasket there. Has anyone ever had this where a brand new engine came without a gasket?