You can take a look at the thread for this airplane in here, thread is "It's Here and It Looks Great". They're lots of people who have used gas engines on the T'Craft with varying degrees of success, both mounting and flying. Sounds like a PITA to me... For my money the best engine, and what I have on mine, is the OS Max 120AX. It flies just great with it, and the engine is absolutely trouble free. I mounted it in about 15 minutes, hooked up the throttle linkage, another 5 minutes, and flew it. Never even had to touch the needles. W/ 14 oz of lead in the nose and a total weight of 14lbs and 4ozs, it's a floater!