Hi all - new member here. Last year I had my dad's old 1985 K100 Basic shipped to me as a rehabilitation project (the bike I rode occasionally as a teen). Only has <4k miles, but after sitting for over 30 years, it came with some issues lol. I made good progress - replacing the tires, replacing the fuel & brake lines, getting the front brakes working again, greasing the driveshaft splines, restoring the gas tank that was full of rotten rubber, etc - but I'm far from done.
Two things I'm working on now:
1) The rear brake. Unfortunately the old 13mm master cylinder was locked up with corrosion, so I can't rebuild it. And there are no replacements available out there. So under some guidance, I swapped in a 16mm version from EME....but it seems like the push rod (from the old 13mm) isn't engaging the plunger on the 16mm? I have to push the brake pedal waaay down to activate the brake, which clearly isn't right. And it seems I can't screw in the push rod far enough to make for a normal brake pedal stroke. Not sure if this is a simple fix with replacing the push rod, or if I'm mistaken and the 16mm actually is not a workable replacement for the 13mm on this bike.
2) Steering head bearings. Got the old races out, got the lower bearing off the stem....so seems like the hardest part is behind me! But when I pounded in the new races, using a race driver from EME, the lower race is seated about 3 or 4mm recessed into the tube. I assume that's normal, since it's seated on the shoulder inside the tube and it's the same dimensions as the old race. Or do I need to extract it again and then re-seat flush with the tube bottom?
And I would love to hear any advice for must-do things before I try to fire this baby up. For instance, I did not get into the oil/water pump...but I will if that's likely to be a problem after 30 years of sitting.
Thanks for any help!
Rob
