Cross-posted from K-Bike forum....

I have a 1986 K100RS with EML GT2 and during the service the mechanic noted "more than normal bits of metal on the drain plug and the oil was very shimmery." As I mull options for either rebuild or replacement, (if it comes to that) I'd like advice on whether other K-Bike transmissions will fit and whether there is any reason why one year would be a better choice than another? Does the gearing differ from year to year? Would one gearing be better for sidecar applications?

One note, I did experience two instances over the winter of the bike not wanting to shift out of 2d gear. Both times after I stopped the bike shifted just fine. And it hasn't repeated in more than a month (about 1000 miles).