Vintage BMW Motorcycle Owners

10 volts way too much. That draws a lot of current not healthy for dynamo, battery and all your lights.

The charging light is in effect measuring the difference between dynamo voltage and battery voltage. In your case the battery produces 6 volt and you dynamo obviously produces voltage too. When you meassure 7 volt across the charging light and your battery is 6 volt then the dynamo is 13 volt. Way t...

Thanks for the pictures and the comments. I think you are right, a lot of stuff for our bikes sold in Germany comes from cheaper countries, Poland, Turkey, China, just to name a few.

Do you have any tips now? It's a job in my near future. Did you get it nice and tight but not too tight for putting it on?

The R25 has a simple battery powered ignition. No magneto in these. I think you have the Ignition coil connected to 30/51 on the switch plate in the headlight, which is directly connected to the battery, instead of terminal 15/54 which is after the switch, so it will be turned off when you pull the ...

Check if the hole where the seal goes had clean and undamaged walls. If so, install the new oilseal without any RTV or whatever. That stuff is a bit slippery and the seal could easilly slip out again. Those seals are designed to be installed dry on the outside and with a smear of oil on the inner, o...

Well, the BMW /2 crankshafts flex quite a bit at higher rpm's. BMW even had to use the barrel bearing in the R68-R69S because of this. I don't know if a roller bearing would be able to cope with this flexing.

The idle mixture screw regulates the air. Out is more air, thus a leaner mixture, in is rich.

But that really looks like oil. So either valve guides, piston rings or a damaged head gasket.

Average size of a German man in 1960 was 1.79 meter. So there is your answer.

First, your R50 has a magneto ignition. It is totally independent of the battery. I guess your high tension leads are stripped a bit too long, with the copper touching or almost touching the cover where they are connected to the coil. Or it is some silly little thing like you forgot to press down th...