I just got the Tower Hobbies .75 installed on my UCD60. The chin tunnel was just a little too narrow for the fat muffler, so I had to widen it a little. I really don't mind fully inverted engines, but that tunnel was just too tempting a place to place the muffler.

My question is: would a little bit of down thrust be bad for this airplane? Because of engine being mounted roughly 30deg. down, it's kinda difficult to dial in just right thrust. I get 1deg. of down thrust for every 2 deg. of right thrust I put in.