Two R75/6s with 9/10 R75/5 Carbs

[sblaylock]

In the last two weeks I've had two customers come by with their R75/6 and both of them have the /5 carbs. Was this one of those BMW things where the early R75/6s had 9/10 carbs instead of the 13/14 ones just to clear parts? It seemed odd to see two with the same wrong carbs, which made me think they are actually correct for those bikes. The one from today has a build date of 12/74.

Thanks,
Scott.

[srankin]

Is it possible the two bikes were first year bikes, and perhaps BMW used up the remaining carbs they had on hand?

I don't know about the bikes but I have a 2011 335I convertible. 2011 was a style engineering change year for the car.

Looking at the specifications, by rights I should have a certain engine in the car but, I have the last year engine instead.

I kind of think if BMW at the time had a crate or two of early carbs, they would have used them instead of stored them. Just a thought, I could be wrong. St.

[sblaylock]

That was my thought too, but wasn't sure. I didn't get the VIN from the first bike, but will when he brings it by for service next month and check the build date.

Thanks,
Scott.

[snowbum]

FYI....the R75/5 AND R75/6 may well be seen with the /9 and /10 carburetors. Those carburetors work pretty well. It is the /3 and /4 carbs, used on the early R75/5, that were so troublesome. Some will be seen with a c, others with a C, on the very top. The differences in construction of the /3/4 and /9/10 are rather large...they will look pretty much the same though.
https://bmwmotorcycletech.info/earlybingR75CV.htm covers the /3 and /4, in-depth, with some information for many others too.
There is a substantial section on the BING CV carburetors in: https://bmwmotorcycletech.info; scan way down to the Technical Articles List, then scan way down to the fuel section. There are over 20 articles in that section.

The R75/7 had all the important fixes in their carbies.

In answer to another question, it is true that BMW tended to use up parts/items still in production inventory. The amount and depth of that policy varied considerably depending on the date/era. In some places in my site I list the model and serial number for changes. That would get obnoxious if I did it majorily though, so I usually do that when it's important.

[sblaylock]

Last year I had a customer come in with 3/4 carbs and I did everything I could based on those articles to get them to run consistently. After a long battle and a disappointed customer I swapped them out for a pair of 9/10 carbs I had and sent him on his way - very happy I might add.

Both /6s with the 9/10 carbs run great and the owners had no idea. If they're happy, and the bike runs great then I'd have a tendency to not suggest a change.

Thank you for documenting what you have on your website. You provide such a vast amount of knowledge on these bikes, I'm not sure where I'd turn to solve issues you have so thoroughly explained.

Sincerely,
Scott B.