Please bear with me, first post on this forum. I have a new to me 1990 K75RT, and have an odd vibration problem. Above 4100 rpm there is a buzzing type vibration, that comes and goes in a 1-1.5 second cycle while maintaining constant speed. A bit more noticeable the faster I go. Not terrible, but clearly there compared to my 1987 K75C. And annoying. I assume engine related, as it is there at the same rpm in 3rd, 4th and 5th gear regardless of speed. Thus far, work I've done includes a new rear main seal, clutch reassembly with painted marks staggered, alternator rubber bits replaced, driveshaft and final drive replaced with serviceable used units, throttle bodies synch'd, (pretty close, although it seemed I had to unscrew the middle one a lot, like 3-4 turns, to get them nearly even on the manometer.) Motor mount bolts tight.
The second problem is a small oil leak, that is coming from somewhere above the hole that the oil pressure sensor wire comes through. A few drops on the ground right in front after parking it. Not by the oil filter cover. I used the baby powder technique to locate it. What's up there, and is it worth going after? i.e. anything terrible likely to happen if I ignore it? No coolant in the oil, no oil that I can tell in the coolant.
I appreciate any help you give the new kid.
