Vintage BMW Motorcycle Owners

The R12 diagram shown is ok to follow. The light switch in the headlamp is obviously different to R12 but the numbers still coincide. The two lights shown with inline fuse are sidecar lighting. 31 is the earthing and runs to the engine casing, the horn earths to the bars through the switch. I did pu...

I don’t have a spare but did do a drawing for someone some time ago if it’s any help. If I remember correctly I didn’t have a thread gauge at the time to be sure of the thread pitch but if you have the casing it will tell you.

Not sure which model exactly you refer to, maybe your R71? The early bikes, R52/62/11/12 and R71? etc have a low beam/high beam toggle switch operated by cable as you describe. The headlamp and side lamp is turned on by a separate switch on the rear of the headlamp or as R12 and most later bikes by ...

I’ve had one rewound with new condenser in the UK. Ribblesdale Auto Electrical in Preston. They did a good job on that part of the mag but couldn’t source new bearings, needless to say two years later the bearings started to fail. I sent it to BMZ Magnetzünder as link above and they sorted it. The b...

I think original. Mine is known to exist as far back as 1946, my photos are not the best but it does have the same manufacture marking and DDR stamped on it. The lens does have a slightly different edge, a little deeper than yours. My lens also is like new.

Is your outer seal case the same as mine in the photo attached? I don’t know for certain if this part is original on mine but it is machined to accept a modern readily available rubber/nitrile oil seal, it works ok as well. Otherwise I don’t know of a supplier for this part. The felt used for the or...

Mine is closed or metal side to gearbox. Now the bike is out of storage I have been able to measure the speedo cable, it measures 680mm.

I believe SAE 30 was specified for winter and SAE 40 for summer use in engine and gearbox. I guess with your location the summer use would be good choice. You need an oil suitable for these old engines with low detergent, this allows the sludge to fall to the sump as the early engine has no filter a...

The info I have says .06 to .08 mm. The bore size is usually to size (eg 78mm) and the piston will be .06mm less to give the correct clearance. My original piston is 77.94mm to give the .06mm clearance.

Photos of chain driven engine case.