I don't think so. From all I've read over the years, the rocks in a bucket sound is typical for KDX's. although it doesn't seem to cause a problem (as long as you keep clean oil and a clean air filter).
I just noticed how my clutch basket is loosely connected to the big gear behind it (that's driven by the primary gear on the crankshaft) and think that's adding to the engine noise.
I did a total rebuild, bearings, seals, re-nickel, piston & rings etc.
Couldnt get rid of that good old KDX trademark.
If it doesnt clatter its not a KDX.