This looks like a newer post so looking for help. I have a G38 that I do not know the history. It came on a Dynaflite PT19. Awesome flyer, fun. But the engine is driving me crazy. It is fickle to start. Does not always start, when it does, runs great. Two main issues:

1) Flying along, all is well and it will start sputtering, running rough then cold turkey quit. Get it on ground and sometimes will start again, sometimes not.

2) Just won't start at times.

I had carb rebuilt, spark looks good, changed fuel, plug.

It honestly acts like when I once had a prop strike and sheared the key on the shaft, making timing all wacky of course. Tries to start, pops, but just is not consistent. It almost seems like the timing goes in and out. Anybody think this is at all possible? I also replaced all fuel tube, but maybe need to revisit the tank.