I am having to sell my girl. It has some topside engine damage and metal shavings coming out of the crankcase. I am not a bike mechanic by any means so I do not know what is going on, but the motor still runs perfectly fine. I would like to sell it whole for anyone who can fix it, but i am willing to part it out. If you are interested, send me a pm and i can send pictures.
Do you know if the metal shavings are steel or aluminum?
Are there any rubber chunks on the screen behind the left side oil drain plug when you drop the oil and pull screen out?
Any rubber chunks indicate the counter balancer is deteriorating and coming apart.
The counterbalance shaft then moves to the left and starts rubbing on the engine case, eventually to chew a hole through the side.
This could be the source of aluminum shaving in your crankcase.
If caught soon enough, the engine can be pulled, the case halves split, and the rubber counter balance parts can be replaced.
I believe a couple of members have reported engine cases holed like this have been repaired with Cold Weld epoxy or some such similar product.
Good luck with finding the problem and/or selling the scoot.
Wish I lived closer as I would love to have a bike for spare parts, and just generally to be able to experiment on and not have my only ride out of commission while I do so. I especially like the black tank with the red ribbon on most pics of the '85 models I have seen.