/6 parts crossover?

[boxedbike]

As I said in some other posts I just picked up a 76' R75/6. Are all the /6 bikes the same besides the motor? what if any parts are the same? if they are the same but with different engines, it would make parts shoppin' easier.

Also what is the story of the R75/6? Is this a desirable bike? I really didn't do much reasearch b4 I bought it. It seemed like a good deal for $200, even thought it's completly disassembled. dont get me wrong, I may be BMW ignorant, but I wont screw up a good thing. if the bike I bought is in good enough shape I will restore it the right way. :rocker

[R100RS]

For all practical purposes, all of the /6's are the same except for the jugs and pistons. There may have also been some different final drive ratios for the different sized engines.

The transmission internals in the '74 models are different. They have a standard kick-starter whereas that became optional in '75. Also, many of the internals in the '74 model are no longer available and are not interchangeable with later models. However, any model year '74-'80 transmission can be bolted to the back of your bike. Having said that, the '74 transmissions are to be generally avoided.

I'm in the process of rebuilding a '74 R90/6 (it had been sitting 5-6 years and had been put away with transmission and other troubles) and am very close to having it back on the road.

I don't think the R75/6 is at all undesirable. I prefer the 900/1000 size, but I think you will end up with a very nice bike when you're done at a great price. The only advice I can give is to join the Airheads (http://www.airheads.org) be patient, ask questions if you need to (the AirList is invaluable), and don't put any garbage components back in. Since it's all apart you have the opportunity to go over everything with a fine-toothed comb and replace parts as necessary. Then, there will be no surprises and you'll have an extremely reliable bike. Oh, yeah, buy yourself some brand new gas tank hold down bolts, regardless of how good the rubber looks. DAMHIK

[lkchris]

For all practical purposes, all of the /6's are the same except for the jugs and pistons. There may have also been some different final drive ratios for the different sized engines.

Yes, different axle rations; transmission gearing same.

Carbs different, too.

[James.A]

There is an EO change in the '75 model year with respect to the fit of the cylinders into the motor cases. Your 1976 airhead would have the "improved" nomenclature where the cylinder base spigot is fitted into the motorcase and sealed with "O" rings. The earlier set-up has flat gaskets that seal the cylinder base to the outside of the casing where the jugs drop in. The fly cut of the casing on the later design is slightly larger, and the parts do not interchange.

Also, 600cc bikes have different front brakes, heads, and carbeuretors

Other than that, I know of no other issue with parts inter-change on /6 models.

[James.A]

I'd part that bike out to help save other bikes and hunt out a running airhead. That way, you could enjoy ridin' and renchin' and rebuild a bike over a protracted time frame.

[boxedbike]

Yeah I've thought about parting it out. to be honest I havent looked at all the stuff yet. the bike is boxed up nice and im about to move. as soon as im set up in my new place i'll have a shop to work. once I have a look at the overall condition of the bike, ill make my decision.
I also have another bike thats all boxed up. its a late 60's harley sportster chopper, its a TOTAL mess. I sold the heap to a friend but i'll still end up helping him out. ontop of that im fixin up a buell to sell. so I do have allot of projects. :doh but the buell is an afternoon of work, and the chopper is a long term thing for a buddy. if the bemmer is in ok shape, i think I'll give it a shot. who knows, I could be advertising /6 parts next month. :dunno