1 Electrical problem, I think? K100RS 4V Sun Dec 27, 2009 10:34 pm
Pencilhead
active member
I have a problem with my ’91 K100RS 4V. I’m in Maine and getting to a BMW
mechanic is difficult so I’m hoping for a lucky break and someone has an idea
what’s wrong. I’ve tried to include everything that happened in the proper
order (I think I remember it all).
So, I turned on the key and all the lights came on as usual.
I then turned the kill switch to run and on came the fuel pump as usual. When I
pushed the start button, there was a click and all the lights went off but the
engine didn’t start. After flipping switches and turning the key, I realized
that by putting the bike in gear and moving it with the clutch out something
happens that allow the lights to come on and I can start the motor. BUT, when
the engine starts ALL the lights go out again. When you rev the engine up to
3-4K the lights flicker back to life as long as the RPM stays up. The other
thing that happens is that the speedometer shows speed that increases with the
RPM/Lights WHILE THE BIKE IS SITTING STILL? And, of course the odometer is
moving with the speedo.
I can’t think of what could cause this. The engine runs
great once it starts. The battery is fully charged, the alternator is charging
well. I don’t understand what connection there could be between the rocking of
the bike in gear and the electrical system.
I hope someone has some helpful input that might direct me
to a solution before the snow here melts.
All the best to everyone during the holidays!
mechanic is difficult so I’m hoping for a lucky break and someone has an idea
what’s wrong. I’ve tried to include everything that happened in the proper
order (I think I remember it all).
So, I turned on the key and all the lights came on as usual.
I then turned the kill switch to run and on came the fuel pump as usual. When I
pushed the start button, there was a click and all the lights went off but the
engine didn’t start. After flipping switches and turning the key, I realized
that by putting the bike in gear and moving it with the clutch out something
happens that allow the lights to come on and I can start the motor. BUT, when
the engine starts ALL the lights go out again. When you rev the engine up to
3-4K the lights flicker back to life as long as the RPM stays up. The other
thing that happens is that the speedometer shows speed that increases with the
RPM/Lights WHILE THE BIKE IS SITTING STILL? And, of course the odometer is
moving with the speedo.
I can’t think of what could cause this. The engine runs
great once it starts. The battery is fully charged, the alternator is charging
well. I don’t understand what connection there could be between the rocking of
the bike in gear and the electrical system.
I hope someone has some helpful input that might direct me
to a solution before the snow here melts.
All the best to everyone during the holidays!