Hi,

I'm quite a new guy in the RC airplane universe. I got a student airplane with a OS 46-FX engine. It flown twice in the past and seems to be in great shape. When I turn the propeller, it stuck when the piston is at the top of the cylinder. Nuts of the cylinder head are evenly tight. I unmounted the engine to realize that the problem occurs only when the cylinder head is on and tight. Is it possible that the cylinder head gasket went tinner with the time and that the piston doesn't have enough space at the top to make a complete revolution freely?

I'm a french speaking Canadian... sorry for mistakes!

Thanks!