Airhead electronic ignition failing
 

Hello! I’ve got a ‘74 R75/6. I’m the 3rd owner. The original owner added an electronic ignition. That failed on me after a year of ownership. I put in a new one. That failed 4 years later. I’ve read “they never fail”. Am I just unlucky or could there be something else sabotaging the EIs? Sorry, I don’t know the brands I’ve had. Thanks.

I've had two electronic systems fail on airhead twins, both of them Boyer Bransden.
They didn't entirely cease working, just frequent misfiring.
Both occasions, went back to points and the problem disappeared.

Stick with contact breakers
 

I’m guessing that you are not mechanically inept, otherwise you would probably be riding a modern bike. So why not stay with points? BMW cb systems are well made and reliable. Spare points and a capacitor are cheap, easily carried with you and can be fitted at the side of the road if necessary.
After my original Hall effect trigger died, I converted my 1993 R100GS PD to run on points many years and well over 350000 miles ago. I have never had an ignition breakdown since.

A lot to be said for that despite all the 'never have to touch it again' advertising copy. I've stuck with points on almost all my old clunkers - 2 and 4 wheel - for reliability and they've been as reliable as any other bit on the bike. My rule of thumb has been to stick with whatever the factory used initially. I'm not convinced that a lot of the aftermarket conversion stuff is as well developed as they claim and wouldn't be good enough for o.e. fitment.

it is not easy to help you. You don't write where you come from (language), don't know what kind of ignition you have, have no pictures, you say nothing about the general condition. Can you screw on oldtimers? Do you know the technology? Do you know about electrics?
https://www.youtube.com/watch?v=f0a6XiSxC3Q


@a ‘74 R75/6.
Remember you not only have a "new" alternator but probably also holds 50 year old cables and switches on the motorcycle. To travel you need a reliable motorcycle. After almost 50 years of "tinkering" it will probably need to be rebuilt.

- also: bearing camshaft (the ignition point is then no longer correct - depends on ignition)
https://www.realoem.com/bmw/en/selec...&model=R75%2F6

- Hall effect trigger
https://q-tech-shop.de/c/boxer-r-2-v...ngsteile-serie

That not only costs money, but also a lot of specialist knowledge otherwise it will always be a tinker motorcycle.

The experts for airheads are now more then 70 years old and some of them are no longer alive. A travel forum will be of little help here.


My advice:
Find someone you trust in your country and who can advise you sensibly with older BMWs.

You meet this people on classic motorcycle events, mostly less on the internet.
But it's not sure if they screw it for you.

There is also a good airhead-community with documentation in the UK.
Technical documentation (in german) can be found here (account needed):
https://forum.2-ventiler.de/vbboard/...p?7-DB-Technik

That can have a lot of causes, one can speculate a lot.
I prefer to measure.

Wish you success! :thumbup1:




https://gallery.2-ventiler.de/vbgallery/v/treffen/boku/
https://gallery.2-ventiler.de/vbgall...schoenstebild/


https://www.youtube.com/watch?v=Z6icp3UIgrg
https://www.youtube.com/watch?v=TGgH24rbI_4
https://www.youtube.com/watch?v=E9UC3ZUtoKw
search for: boxerkunst

I recently upgraded my R100GSPD ignition with the computerised Wedgetail system, which replaced the hall sensor (bean can) and ECU. It took an hour to fit and set up, and solves several common problems. I'm a complete novice, but it was easy to do.