Vintage BMW Motorcycle Owners

Went for a ride yesterday and the nail key in my '55 R50 is spinning rather than clicking lights on to the left or right. My gen light would intermittently come on as RPM's rise vs the opposite .. I assume the problem with the ignition switch is related (both new symptoms). The Rocky Point keyed ignition module came on my 75/5 years ago, but I would "prefer" to stay stock on the R50 unless experience from others says the keyed replacement is a wiser option. Any advice (parts needed, how to go about it, what to be cautious of, DON'T MESS WITH IT) before I dig in would be appreciated.

Thanks, Chris

Hi Chris-
You're asking for opinion, so here is one!

If you would prefer to stay stock then do so, all the parts, from key to terminal board, are available these days.
If much needs doing, it's a clean delicate type of work, rather than a greasy heavy lifting work; so patience and a keen eye are the mindset to adapt for the task.

From what little you had to say about the issue, my initial guess would be the plastic insulating washer, (located between the contact plate and key switch barrel) is missing or perhaps has broken up.
I've not seen this happen, but if it were not in its location, I believe it would produce the symptoms I think you are describing.

The insulating washer has two jobs- It both separates (electrically insulates) the key switch from the contact plate, and is also the mechanical connection by which the contact plate is moved between no lights/parking light/headlight.
The insulating washer has an ID the same as the key barrel, and an OD the same as the ID of the contact plate, and flats on the bore of both mean moving one moves the other; so without the insulating washer, the key/key barrel would rotate freely within the contact plate, without moving it between any of the contacts on the topside of the terminal board.

Like I said, my 2 cents.
Best-
George

Since you're already familiar with the Rocky Point setup, Ill just remind you of one thing: Since the /2 use magneto ignition, the RP switch only operates the lighting system when used on them. You will need to install a kill switch or button to operate the ignition.

Thank you for the helpful replies. I will get after it when I get back home from a long weekend trip.

The slot on the ignition key may be worn or most likely the 2 slots on the key lock are worn so when the key gets turned l/r the contacts in the switch does't move

the key lock on one of my bikes is worn and the headlight does't always turn off when I recenter the ignition key
If I lightly push downwards on the key while turning off the headlight it will turn off the headlight
Tommy

Had a chance to look into my issue yesterday and found a few easily remedied problems (thankfully). The key wasn't fully engaged (thanks Tommy) although it appeared to be. It required a significant push, so I added a drop of oil on the key and in the receiver and it engaged easier. I found the black/white parking light wire disconnected from the board as I was snugging up the wire connections. The most significant "DOH" moment came when I found a brown wire pinched between my recently rebuilt and reinstalled speedo and the U bracket that holds it in place. Disappointed in myself for that one but pleased to find a simple solution.

Thanks again for the suggestions,
Chris

New Key Switch.

position the 'donut ' as it's intended to be. rat tail file the allen head threaded area down. mark the donut where 1 tab will bend over when installed. carefully hand file 2 plains so the tabs LOCKS the donut in situ.

thread allen head to threads on lock.
counter sing or use a ball ended grinding bit to indent the key shaft.

now you are setting the key to be stable and in a positive position. it won't rotate when you turn the key. IF ........ you don't you'll soon find out you're in trouble .

grind down that little TIT that's sticking up.

if you don't , your key tumbler will NEVER seat squarely.

Way too complicated. Secure the aluminium donut within the four tabs with a hose clamp. In and out in 20 seconds anytime. 10 years in an R75/5 and 5 years in an R60/2, no problems.

So happy for you

..... SO what do U care what I do

to improve my own bikes electronics. Are you going to nit-pick all my threads about wiring, speedo, tires, brakes, the seat I want to use and such ?