I had a GMS76 and it was one of the better engines I've owned. No problems what so ever... Being that it is a ringed engine I would use an electric starter to start it simply because it won't suck the fuel up as easy as an ABC engine.

As for break-in I ran about half a tank through it on the ground then went flying... I never had a single dead stick with this engine.

As for props it likes the APC 13x6.