Vintage BMW Motorcycle Owners

There are different pictures of the repro SUM carbs for R12 from the various suppliers. Some have brass knobs, others not etc.

Must I assume there are different new repro SUM carbs for R12 on the market?

If so, does anyone have bad experience with either one of the repros? It's a lot of money so I'd rather buy a good repro first time right.

Thanks in advance,
Peter

The originals used a brass float bowl lid nut, a restored original will always be superior in quality and function to a copy in my opinion.