Question: I just did a compression check (with an automotive comp tester) and found 125 on the left and @ 95 on the right on my 1992 R100 - the bike burns no oil (although there is slight oil showing from the right push rod exhaust seal), doesn't smoke, good acceleration for a 20 year-old BMW - It rides well (did Michigan to California trip Summer 2011 with no engine problems - needed a new drive shaft, but that's another story) - Are rings/valve-seat grinding/guides needed? The bike has 64K miles and has been maintained with fluids, adjustments, etc. Not sure where to take this airhead, but it's been a great ride in my 8 years with it -