Aaah, learn sumpin every day,lol....If it the "equivalent" it should burn the same or very close.
Brown below the rings can be blow by, which could mean the rings are shot.
Some engines don't have needle bearings up top where the rod connects to the piston, some have a bronze bushing.
http://motorbicycling.com/f30/bicycle-engine-total-tear-down-391.htmlthere was only a tiny bit of brown, and the rings were sealing very well.
it was nice to see that mine did have needle bearings.
btw, before i take EVERYTHING apart, do you have to remove the reduction gears to open the case?