Vintage BMW Motorcycle Owners

this is the third bike this has happened on... pulled the slides and found them scored... somewhere i read about re-sleeving the bores in the carbs but that seems extreem. the problem went away in the other two bikes eventually after sanding the bores and the slides, but the whole thing remains a mystery. am i the only one out there that has this problem? any help?.... jim
Warping of the carb bodies over time, causing binding of the slides and galling of the bore, is common. Some blame over-tightening of the flange nuts.
I have sanded one slide twice in three years on a friend's bike, and just sanded one slide on my own bike last month. In these cases, when the carbs were removed, the nuts were not very tight at all.
For about $75 per carb, Triton will true the bore and put a brass sleeve on the slide. http://www.tritonmachining.com/
This results in perfect action and no galling, but I have not heard how permanent it is. If the carb body is really the culprit for deforming, it would seem that the problem could happen again.

allen thanks.... i thought i was the only person out there that had some of these problems with these old bikes. now i know i am not crazy, but actually have company.....jim

... For about $75 per carb, Triton will true the bore and put a brass sleeve on the slide. http://www.tritonmachining.com/... Here's a page by Ben Friedl showing what Triton does:
http://bensbmw-r25-3.freeservers.com/Recon%20Carby.htm

Howdy Jim, you are not alone, believe me, i'm just this minute back from a ride after an oil change, grease and a few small adjustments and those bloody carby's are at it again, spilling overpriced gas all over the garage floor.

this is the third bike this has happened on. the first was a 52 R68 the second a 67 R60/2 and now the 67 R69S. replaced the cables with ones from vech to get the proper sheath length and cable length. cleanned the throtle gearing and after about 20 minutes the throtle works very hard. on finnishing the ride i pulled the slides and found them scored. the notches were put on on the right position when re-installing the cables. somewhere i read about re-sleeving the bores in the carbs but that seems extreem. the problem went away in the other two bikes eventually after sanding the bores and the slides, but the whole thing remains a mystery. am i the only one out there that has this problem? any help?.... jim