How much metal dust is commen with a brand new engine. I just heat cycled my new GPX for three runs. On the third run I took it for a couple laps(no crazy revs)and let it cool. Then I let it warm up again and changed the oil when it was hot. I have a magnetic drain plug(which I did not have with the first engine)and it had some metal dust along with some gasket material stuck to it. I know some is normal but there was a glob the size of a small BB,but all dust?
If you ever get a chance to remove the clutch cover or split the cases and look around you will see why you have all those shavings. I don't think they pay any attention to tight clearances in these china engines. The clutch basket moves around too much and I have seen them almost rub the head off of the detent bolt b/4. What you're seeing probably isn't coming from the top end.
don't worry it's normal all new engines do it to some extent i always drain my oil thru a paint strainer to see what i get as long as they are not copper i don't worry copper is used on the main bearings