@admiralpepega Stephanos, The black wire provides power to the regulator and senses the voltage at the battery for the regulation. Connecting it t...

@thundermotive Brian, Your stearing head bearings are industry standard 320-28 tapered roller bearings. They are available at any bearing supply h...

81RTBC, Since the tail lights and turn signals are interacting, the problem most likely lies in the wiring they share. This would be the ground wir...

Subman, Do an internet search on 'grease gun needle nose adapter' and lots of options pop up. One style adapter will fit into the standard zerk noz...

A little background information here might be useful. The neutral safety switch in the transmission allows the starter relay to be energized only when...

These plugs are not a common size, 16 mm by 1.5 mm pitch straight thread (not tapered pipe thread). One should be available from a hydraulics supply. ...

Blue-1 It sounds like you are a victim of the Revenge of the Pulse Air System. 1980 was the first year BMW installed an air injection system on the...

Hoobie7, I've been thinking about your problem for about a week, and I have some ideas. Let's find the solution. The specs on your lights are 11 to ...

Julien, I just had a thought. If you don't have a schematic for your bike, here is a web page for one. Any electrical problem can look hopeless witho...

When an R90S, one of the most beautiful bikes BMW built, won't start, the forum should leap into action. Let's try to figure this out. I am using my C...

JohnB, You have received many replies to your request for assistance that assure you that this is a common problem and not a big concern. The voltm...

If your VOM is telling you the truth, that diode is open i.e dead. OL ohms means overload, no current flow, open circuit, DEAD. 273K ohms is the equiv...

Smoky, That, as it turns out, is a difficult question. That bike falls into a transition period for BMW engine/frame numbering. Your photo does not...

13). Is this the brown wire from step 12)? All of this points to the neutral switch and/or its wiring. As a quick test, pull in the clutch lever an...

In response to your post from this lats Sunday: I am working from a Clymer manual schematic for a 1974 R90/6, I hope the wire color code matches what...