ORIGINAL: KLF1292
I recently ran a tank of fuel through the Evolution .46 engine on my Alpha 40. Afterward, the engine and the top portion of the fuse. area directly behind the engine were covered with the oil. I have a Dubro Ehaust extender/deflector attached to the muffler directed down and away from the wing and fuse. I wouldn't expect that the oil would have ended up on the engine and top fuse directly behind the engine. I noticed a few bubbles a few fins below the head while the engine was running but didn't think anything about it until I noticed the volume of oil aftward. I suspect some sort of leak but I don't know where its coming from. Any suggestions?
----------------
The bubbles around the head junction need your attention. Check to see if they are coming from the head/cylinder junction, or if they just happen to appear in that area because of prop blast.
If it is coming from the cylinder head/barrel junction, you need to carefully tighten the engine's head bolts. Be gentle, but firm and evenly apply torque to all of the bolts in a cross hatch pattern.
Two-stroke carbs spit fuel, so even if you have the engine's exhaust routed well away from the model, you'll still get some oil on the plane.
Glow fuel engine oil does not burn during combustion and 1/5th of the fuel is oil, so if your model has a 10 oz. tank, you can expect two ounces of oil to be lost through the engine's exhaust and whatever escapes from the carburetor while spitting. The exhaust can be routed away from the model, as you have done, but about the only thing that will help with the carb spitting problem is an (argh!) air filter. A company named Bru-Line makes filters that can be adapted to most carbs.
Personally, I just take a lot of paper towels and window cleaner with me when I fly and do not worry about the model being coated with gook. It is just a part of flying with a glow engine. This is why the electric/gas crowd call them "slimers". <G>
Ed Cregger