Capn,

Usually if the engine is uncowled, I mount the engine upright as in the picture of the Homelite 30cc on my Ultra Lite Stik 120. If the engine is cowled, like the picture of my GSP Katana with the Kioritz 23.6cc, I mount it inverted. The plane was inverted on a work stand when I took that picture, hence the confusion. I've never noticed any operational difference whether they are mounted upright or inverted.

Actually, it also makes me a bit nervous also to mount the servo next to an ignition engine. The ones I'm running with the servo next to the engine are running on "Gas/Glow", and don't have an ignition system. A lot of people do mount the servos next an engine with an ignition system with no problems however...

AV8TOR