Normal two stroke sound or knock?

There is a weird knock that happens on 2 strokes on deceleration with closing throttle.
I think it is just pipe backfires but I hear it from time to time.
Liquid cooled doesn't get so much of that Ping-Ping noise.
The DT200 bike has a double thickness pipe too, it is absolutely silent. Well, not really but pretty close!

Sheesh, with all these guys standing around watching you rebuild, ya can't get away with NOTHING!
Stop giving out beer and they'll go away.

We used to call the excess RTV globs "salamanders" because that is what they look like inside an engine or gearbox.
Seen a few kill the oil pump (lucky we don't have 'em!) and plug an intake to ruin any porting effort.
 
Sounds good to me!

The globs or salamanders, that I call dingleberries, (things that hang on the hairs or your anus, when the wipe is incomplete), can break off and get into the most inoportune places and destroy a motor.