Originally Posted by killfile
I've heard a ton about cranks seals that go when these sit too long. I believe I'm running the original crank seals and I haven't had any issues with that so far, but I'm always suspicious. If you are restoring a '75, then you probably already know about the 1200cc / 1400cc oil issue that was delightfully solved by '74. The earlier bikes did not have enough oil to lubricate 5th gear at all, or 4th gear as well is it should. The factory issued a service update that added a rubber dam in the gear box to allow the oil level to be increased to 1400cc, lubricating 4th and 5th gears. The '75 should have it, so you should be running 1400cc of gearbox oil.
Yep I've read about the gearbox oil capacity at length! My parts bike '70 has the 1200cc capacity, the '75 1400cc. Haven't looked in the gearbox to see if there was oil in it, but the oil tank has plenty! This give me hope that perhaps the crank seals are in decent shape. Currently putting in new fork seals and cleaning carbs (gotta pickup some PineSol on the way from work!)