4 replies [Last post]
TSLEM's picture
Joined: 10/02/2016
Posts: 4

I'm new to BMWs and I recently purchased a R80/7. The previous owner re-wired it as a café racer (headlight, tail light, no turnsignals or any other non-necessities. It ran when I bought it a year ago, but would never start for me. Cleaned the carbs and pulled the new looking spark plugs, but NO SPARK. The electric start turns the motor well, but no spark. Where can I find a "how to" checklist on trouble shooting the electrical system? Would it be worth just buying a new wiring harness and rewiring it, but eliminating the non-necessities. I want to build a stripped down café racer, so I just need the wiring that makes it run and have lights. ANY HELP? Thanks!

schrader7032's picture
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6710
Welcome! I'm wondering about

Welcome! I'm wondering about the modifications that were made. If the original light in the speedometer pod was eliminated, then there's a possibility that the bike does not charge the battery when running. You say that the starter turns when the button is pressed, so maybe that's not an issue.

You mention pulled the plugs but no spark. Just exactly how are you doing that? If you pull a plug and stick it back into the plug cap, you must ground the threads of the plug to the engine. Failure to do so can damage the ignition coils. It's a bad thing to run the engine with the plug cap and/or plug not grounded to the engine.

Snowbum has a number of articles that deal with the electrical system. I'll warn you that he is quite verbose and maybe scattered in his writings. But he really knows these bikes well. So, spend some time reading them. You should also consider buying a manual of some kind to be able to do the maintenance. Links that I find are:





Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

TSLEM's picture
Joined: 10/02/2016
Posts: 4
Thank you so much. I'll read

Thank you so much. I'll read them tonight!

mark_weiss's picture
Joined: 11/16/2013
Posts: 173
The engine cut off switch is

The engine cut off switch is in the 'ON' position?



tonyhutchinson's picture
Durham England
Joined: 08/17/2015
Posts: 98
you say the bike ran when you

you say the bike ran when you bought it so you know it should run. If it is fitted with points and condenser check that the points are gapped correctly and that can get spark at the points by flicking them open with the ignition turned on, also have a look at the cables that fit onto the coils to see if they are a good fit and of course make sure the HT leads are pushed firmly into the coils. My guess is it will be some thing pretty basic, good luck



Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.