I have a strange problem with my OS 46 LA engine that I've put in my Kyosho Trainer 40.
Its a nice engine and all...
BUT, for some strange reason the propeller nut keeps unscrewing itself!

Last time it did this in the air, at the start of a loop. I asked a friend of mine to try the plane and do some rolls and loops with it. He did a roll, a slow loops, got more speed and went for another loop.
When the plane was facing the sky we heard a strange noise from the engine, he aborted to loop and started to take it down when suddenly the engine started to scream!
We cut the engine and glided it down. When it finally landed we noticed that the engine was missing the drive nut, washers, prop nut, spinner and prop

I got replacement parts from the local hobbystore, the guy in the store didn't have parts in, but he removed them from a OS 46 LA in display, great service there
I got a new spinner and prop. I used something similar to Loctite on the prop nut this time. But it still unscrews itself every third start. But only 1/3 a turn this time, not completely. I've learned to hear when it gets loose but its still a very, very annoying and dangerous problem.

Anyone got a simple solution?