1970s Airhead

[schrader7032]

Bruce -

I believe there has been some posts regarding model differences, etc., possibly by me. But you only mention the /5/6/7 era, so I won't mention anything past 1980. From what I recall, things to be concerned about are:

- early /5s with small flywheel bolts, 10mm as opposed to 11mm. I've heard about the possibility of the smaller ones shearing off. I don't believe it is easy to retrofit.
- the 1974 model, the first /6 I believe still has the 4-speed tranny...not so good I hear.
- beginning with January 1978 models (/7), the EPA requirements start to creep into the engine. Not a real bad thing, but it does end up detuning the bikes, etc.
- thru 1978, bikes were originally points while in 1979 and 1980, they began to work towards an electronic ignition. They used the "points in a can" for these two years...it might be an improvement or not...
- my opinion of the kick starters in the early years was more of an accessory or something to get out of an emergency. The electric starter was adequate. I also think the Bosch starter is better than the Valeo but not sure if it was used on the pre 1981 bikes.
- the charging system improved in terms of wattage. The /5s were typically only 180w while the /6 jumped to 280w.

Check this site http://www.bmbikes.co.uk/bmwmodels.htm for information on specs, etc. HTH...

Kurt in S.A.

Those are my thoughts...

Kurt in S.A.

[Bruce Frey]

Well, I went and did it! I skipped a few generations of bikes and went from prewar to 1975.

On my next trip back to the USA there will be a 1975 Daytona Orange R90S with low milage and original paint waiting in my garage. Unfortunately, I will not get to play with it for a couple of months, but I am really excited!

Ciao,

Bruce

[schrader7032]

Sounds like you did good! Nice year, and nice bike...I always like the Daytona Orange scheme. I've got a scale model of one I bought at Motobins a number of years ago...that's about as close as I'll get to having one!

Kurt in S.A.

[Bruce Frey]

I have ordered a Clymer Manual. The seller is including the original manual and a book on the R90S. The Bikebandit OEM site does not have part diagrams for the R90S similar bikes.

Are there parts books or Ersatzteillistes available online or from BMW or other sources?

Ciao,
Bruce

[schrader7032]

Bruce -

There are a number of on-line fiche sources.

http://www.maxbmwmotorcycles.com/fiche/fiche.asp
http://www.ascycles.com/illustrated_par ... _main.aspx
http://www.realoem.com/bmw/select.do?vin=&kind=M&arch=0

I prefer the RealOEM site...I find it easier to find what I want. You'll have to select the archive menu to get to the R90S.

There's also a program called ETK which provides the same things as the above. It installs on your local machine. I believe this program used to be what the dealer used to look up parts, etc.

You might want to check this site out if you don't know of it already:

http://www.bmbikes.co.uk/information.htm

This provides a lot of specifics about the various years, paint/colors, specifications, etc. You can also determine the build date of your bike by comparing the VIN numbers. You can also do the same thing on the RealOEM site. Type in the VIN and it'll show you the production date.

Kurt in S.A.

[Bruce Frey]

Thanks......just what I needed!

Bruce

[VBMWMO]

The newest bike I currently own is a 1938.

I am thinking of taking the plunge and getting a more 'modern' bike to play with. The aesthetics of the /2 don't do much for me (unless it would be white with a Steib S500 attached), but some of the 1970s /5, /6 and /7 airheads do look good.

Any suggestions on ones avoid, mechanical problems peculiar to them or special things to look for? I have taken on board the comments from similar threads. I am more trying to understand the negatives than the positives about these models.

The other option may be a Honda 305 'Scrambler' from my youth.

TIA,
Bruce