ORIGINAL: Rodney
I think you mean predetonation, don't you? All internal combustion engines detonate, that is what makes them run. If a plug is to hot, to much nitro, to high a compression can each cause predetonation which is usually defined as detonation that takes place to early in the cycle.
Detonation is a state where the mixture no longer burns, but explodes. The mixture gets ignited by a shockwave travelling through the combustion chamber at supersonic speeds when detonating... leading to dangerously high cilinder pressures. There are no IC engines that are supposed to detonate.
Take the head off your two stroke, and take a look inside. If your engine is detonating regularly, there will be signs: the head and piston top will look rough or even pitted.
Your glow plugs will not stand up long to detonation... if you're not burning plugs every other flight, than the engine is not detonating.
Also, detonation usually happens at WOT, and not at part throttle.
If you can make the sound go away by leaning the mixture, it is not detonating...
You are probably just running it rich, which produces a kind if "crackle" sound, better known as a rich two stroke setting in this forum