Last year I was chasing a drivability problem that turned out to be a fuel pressure regulator going south. But, before I identified the problem ran a leak down test on the engine. Leakdown was 0% on two cylinders and 2% on the other two. Not a sexy bike but eminently useful.
Last year we put a Paralever drive line on it. We swapped the guts from the existing gearbox into a new housing. Nothing was worn. Right now it's apart for a clutch and worn input shaft. It took that long to finally do in the infamous input shaft splines. We found two rough bearings and the splines on the clutch plate worn. The original clutch pressure plates remain basically like new and will be reused. We are going to use a K-1100 clutch diaphragm spring this time since the bike now has the tall K-1100RS gearing. Don't abuse the clutch and learn to shift smoothly matching revs up and down and things last a long time. I don't baby the bike necessarily, as the grinders on the right leg of the center stand and both foot peg ends will attest to. You can ride these things very rapidly, just be gentle starting and shifting and they last a very long time.