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View Full Version : 1975 bmw r90/6 points


dp63130
02-21-2004, 12:34 PM
howdy.. I am trying to adjust the points (gap adjustment)on said bike but having a little trouble.
here is what the clymer says.
1. insert an allen wrench into the alternator rotor mounting bolt.
2. rotate the engine clockwise until the contact points are fully open.
loosen mounting screws securing contact blah blah blah..

So I pull off the cover exposing the points and alternator.. fire up the bike and watch the ignition advance unit spin but I dont see the points moving. At all. Nothing. No Movement what so ever.. but the bike is running. Now I have a bit of experince in mechanics but isnt this impossible? I can go take a quick MPEG of it if you want to see it.. dont points need to move? It is possible that they are grossly out of wack.. The bike has not been tuned for a year and half.

And since they arent moving how can I adjust them to be timed correctly -usually I would just rotate the engine until they open all the way then gap them to the correct limit(.35-.40mm)

Thanks for any help.

kbasa
02-21-2004, 01:07 PM
The backing plate that the points are mounted on won't move a bit, but the little arm that rides on the end of the cam will will be moving in and out to open and close the points. Take a closer look behind the advance weights and you can see it doing it's job.

When you rotate the engine, you'll rotate the shaft to the high spot and then set the gap, just like you described.

dp63130
02-21-2004, 01:14 PM
I can see no movement.. every once and a while it sparks.

but the arm doesnt move at all.

I think I need a timing light and new points.
Thanks.

d

kbasa
02-21-2004, 01:47 PM
Originally posted by dp63130
I can see no movement.. every once and a while it sparks.

but the arm doesnt move at all.

I think I need a timing light and new points.
Thanks.

d

When you rotate the motor, the arm moves and you can set the gap, right?

dp63130
02-21-2004, 01:54 PM
unfortunatly the arms do not move. they are not moving what so ever. I can send you a 500k MPEG showing it.

kbasa
02-21-2004, 03:11 PM
Nah, that's cool.

Pretty strange, though. Especially that it's running....

donbmw
02-21-2004, 09:07 PM
Install and points elimanator kit and you wont have to think about point again. I installed this on my R90/6 in 1987 and it is still going strong.

lorazepam
02-21-2004, 10:21 PM
If they were closed all the time, premature ignition wouldn't let the engine run. If they were open all the time, well that would mean no spark, no ignition at all. they have to be opening and closing in order for the engine to run. Are you trying to watch them open and close while the engine is running? or while it is shut off and you are rotating the engine by hand? I would guess that the spark you see is caused by the points opening and closing. It may not happen every time, but you shouldn't see any spark at the contact points if they aren't moving. I have never tried to gap a set of points with an engine running, I would be afraid of bending or arcing my feeler gauge, or shocking the crap out of myself.