Hello, 

Just purchased a 1985 K100 in need of some work to get it running, otherwise it is in good condition.  Does not want to fire.  My goal is to get it running then decide what direction I want to go with it.  The cafe bikes look nice. 

If anyone has any info on what the major issues tend to be for a bike that does not want to fire, let me know.

Devin

Hello from 6 hours north, pink.  "does not want to fire" can be all manner of things until there are more clues.  Does it turn over but not fire?  Or not turn over at all?  Have you got dash lights so you have confirmed voltage of some sort?  If it's been sitting for some time its possible the fuel pump is seized with black rubber from the vibration damper surrounding it.  Confirm you have fuel to the fuel rail?  BTW the fuel pump will only activate when you push the start button.  If you only turn the ignition on and stand back and look for fuel flow it won't have any.  Pushing the start button activates the fuel pump and once it is running the fuel pump circuit is fully activated.  More info required!

Fresh fuel will be a good start and a well charged fresh battery. Usual, plugs etc as ClubC has said
Try it as BMW meant it to be you will find a very satisfying bike there.