clean it out again, the blackness of the liquid would suggest that the clutch shoes are worn out. no metal in it i hope, that, or silverish particulates would indicate the second speed return spring was eaten and screwed the gearset to some extent.
refill with gear differential oil, puking out the carb suggests a bad ringset.
check for oil streaks on the piston sides or do a compression check. the extra holes are because he took out the silencer/baffle. odds are he also put a larger jet in there.