Originally posted by snsmith
Well, I couldn't resist adding one more idea. I personally would avoid trying to Dremel, file, grind, gnaw, etc. on the screw with the engine in close proximity. One slip and you start Dremeling, filing, grinding, gnawing, etc. on your engine.
I would sacrifice the mount. Get a Dremel fiber cutoff wheel and cut the nylon mount from the opposite side right next the screw shank. When you get deep enough into the mount, you can break off the mount arm and pull the engine/screw free.
See, now you're getting sensible and mature about this whole thing just when we were starting to have fun. PARTY POOPER!!! Sheeez.