I have a 1970's .40 size R/C engine with a dykes ring and plain bearing. I completely cleaned the engine inside and out and mounted it in a test stand with a 10x6 prop. Using SIG 25% castor and 5% nitro fuel it runs great. But after about 5 minutes of running I noticed the head and upper cylinder were beginning to be coated with varnished oil. Also, after the engine stopped, I could hear sizzling from the intake like it was boiling inside. It seems the engine is getting very hot. It had been running slightly rich.
Any suggestions on how I can cool this sucker off???
Thanks, Lee
MECA 5575