ORIGINAL: jaka
When it comes to all the Chinese two stroke engines, like the ASP, Magnum, SK, Kyosho GX and SC with a two part silencers, they are notoriously bad! As the silencer screw will always loosen when the engine gets hot.
The only solution to this problem is screwing the the two silencer parts together with small metal screws and using silicon as gasket.
I've got a couple of Chinese made engines and never had the problems you mention.