My first step was to replace all the fluids. I started with the brakes. The front master cylinder was removed, cleaned in my harbor freight ultrasonic cleaner, and then refitted with fresh fluid. I got it to bleed quickly, and it built pressure, with the front calipers moving easily and not sticking on, but the MC leaked badly from the piston. Multiple removals, and gentle application of scotchbrite pads and 600 sandpaper to the bore didn't improve things. Luckily, my local cycle-salvage yard had 2 k75s! One C, one S. Picked up the whole throttle/switchgear/mc for $80. Cleaned it up, fitted it and the front brakes work well.
I changed the oil and filter (not too dark, no filings) and cleaned the oil off the bottom of the engine. No surprises, thankfully. I changed the transmission and final drive oil. There was a puffy halo of metal on the transmission magnet plug, but nothing large, it was essentially metal powder as I smeared it across a paper towel to check.
I removed and cleaned the airbox, put in a new airfilter. Removed the fuel rail, and cleaned the rust off of it. I removed the throttle bodies and cleaned them. I cleaned the ground wire for the battery, and the gang ground on the frame under the tank. Removed all the front body work, and replaced it temporarily with a standard headlight, and put the gauges on a piece of aluminum plate for now.
I used some permatex epoxy to seal the pinholes, and replaced the fuel lines/vacuum lines/caps/etc..with some fresh gas the bike started, smoked for a while, but ran well as far as I can tell. I took it for a little cruise around my neighborhood and it shifted through the first three gears, ran smoothly, had decent power and stopped smoking. I was feeling pretty lucky so far. With it running, I started making a modified list of issues.
The low fuel light doesn't turn on (tested the bulb, it's ok). All the other lights seem to light appropriately, except I haven't checked the temperature light operation, the bulb works. The odometer doesn't work. I hope to get injectors cleaned and tested soon. The four-pin connector for the pump is a little flakey. I got a later model rear brake master cylinder from ebay. I'm waiting on a new fairing bracket from BMW. Turn signals will have to wait. The forks need to get new fluid, I'm waiting on an injection syringe from amazon today.
I put it back in the shop to pull the FD and take a look at the splines. The final drive spline/shaft is toast. :musicboohoo: