1977 R100RS Big Motor - How To Tell If It IS a CFO?

The Big Motor 1977 RS models had 40mm head pipes and big intake valves, and made a fun ride. Had one, blew it up running unleaded gas on old heads and sold it, big mistake.

I understand that BMW was forced to sell 1977 RS models in California, Florida and Oregon (i.e. CFO) with lower power output, a pollution issue, I suppose.

I'm looking for a project Big Motor 77 RS and don't want to get stuck with a CFO model. What are the ways to tell if it is a CFO? Measure the head pipes? Is there a 'CFO' marking somewhere, like in the VIN? Any other foolproof clues?

TY

CFO should be stamped above the engine VIN by the oil fill hole.

Cfo ???

Ahhh !!! Verrrry good. TY!

Ian Falloon says in his book that the CFO bikes has 38mm exhausts with 40mm clamps plus they had a more restrictive muffler.

Thanx Again

Appreciate the info...

Cfo

Of course, there's another whole story behind the CFO stamping. When BMW came out with the RS model, all the magazines raved about it but predicted low sales because it was such an expensive bike!
Well, the consumers proved that to be wrong and sales skyrocketed! When the Chief Financial Officer brought these facts to the board Of Directors, all were so pleased with the figures that they decided to build some special edition bikes, and in his honor, labeled them CFO bikes.
That's my story and I'm sticking to it, even if April 1st has passed.

Cfo

1074 said:

Of course, there's another whole story behind the CFO stamping. When BMW came out with the RS model, all the magazines raved about it but predicted low sales because it was such an expensive bike!
Well, the consumers proved that to be wrong and sales skyrocketed! When the Chief Financial Officer brought these facts to the board Of Directors, all were so pleased with the figures that they decided to build some special edition bikes, and in his honor, labeled them CFO bikes.
That's my story and I'm sticking to it, even if April 1st has passed.

Click to expand...

It had iron liners and weak-sister oil control rings. I always thought it meant 'Can't Find Oil.'

There's an RS77 group, now on Yahoo I believe, that'll give you more history than you'll ever want to know about the R100RS. I've got Ian Falloon's book as well as Bill Stermer's book on the R100RS.

As the story goes, the first 250 or so R100RS's imported to the U.S. were "big pipe" models. Simple, right? VIN numbers 618001 through 618250 and you should be good. Not necessarily. They didn't all come off in order like that. My particular R100RS was manufactured in 11/76 and is most definitely a "big pipe" model. The first way I determined this was looking at the exhaust clamps which clearly say "42" on them. Secondly, this was confirmed by my BMW mechanic, who is factory-trained and somewhat of a local legend when it comes to working on and restoring BMW motorcycles.

Just looked for the RS77 group and it looks like it's now been reduced to a link on IBMWR. Many of the links aren't active any more, but a list of bikes and owners is listed, but with no further information.
http://ibmwr.org/rs77/