ignition switch and key for '74 R90/6

[focusrsh]

I'm working on electrical issues on a friends' 1974 R90/6 (that is what the frame tag confirms.) First thing I couldn't find is the ignition switch! What I find is 2"-long rod with a plastic handle on top that fits into a hole under a sliding plastic cover, mounted to the top of the headlight shell.

ignition switch key.JPG (83.17 KiB) Viewed 404 times

Online searches all show a regular-looking key and a barrel lock on the side of the headlight shell. Nothing anything at all like this.
Is this a Franken-bike? Or maybe not a USA model?

[Rob Frankham]

I don't know what the score is but that headlamp/switch/key doesn't come from any R90/6. It doesn't even appear to be the switch from a /5 model which is similar but not the same. Could be from an even earlier model or from one of the Russian or Chinese clones.

With minor variations, the headlamp fitted as stock to the /6 series is more or less the same as that fitted right up to '95 on the main stream street bikes. Up from '74 until '85, the ignition switch was fitted in the left side of the headlamp shell/headlamp ear.

To put it another way... don't know exactly what it is but it certainly isn't original...

Rob

[focusrsh]

I just saw a 1971 R50/5 on BAT, that has this same ignition switch. I also rechecked the frame tag and it reads "R90/6" Perhaps someone grafted a /5 headlight shell onto this bike, but that would require huge amount of rewiring. Looks "factory" Another mystery

[Kurt in S.A.]

Not sure this is "proof" but here is the fiche for an R50/5 of the headlight and switch. I don't see any screws in the diagram...I think if they were there they would show.

https://www.realoem.com/bmw/enUS/showpa ... 1328048100

Kurt

[Rob Frankham]

I just saw a 1971 R50/5 on BAT, that has this same ignition switch. I also rechecked the frame tag and it reads "R90/6" Perhaps someone grafted a /5 headlight shell onto this bike, but that would require huge amount of rewiring. Looks "factory" Another mystery

Te main visible change between the /5 series and the /6 is the headlamp assembly (and the wiring inside including the ignition switch. I suppose that there is a possibility that you have some undocumented development bike but I think that's vanishingly unlikely. In any case, the switch used on the /5 (as Kurt says) doesn't have the two cross head screws. I will stick my neck out and give the opinion that this is some aftermarket headlamp or from some other type of bike completely. I now that some BMW afficionados didn't like the 'modern' headlamp unit fitted on the /6 series and it wasn't unusual for them to be given a retro look...

Rob