Hello everyone,

This is in regards to a 1992 k100rs

Well, everything was great for the last 6-7k miles.  Today, I turned the bike on to warm up while I put all my gear on.  Usually it's idling for about a minute before I take off.  I pulled out of the driveway, began accelerating, and the bike died at probably around 4,000 RPM.  I tried to start it back up, but there was no power.  Still coasting, I turned the key off and back on.  The dash lights came on, but were very dim.  I ended up pulling to the side of the road to check things out.  Once pulled over and stopped, I tried the key again and this time had full power.

I still pulled the battery cover off to check the terminals.  The positive terminal was a little loose but had full contact and was still resistant to me moving it around.  The negative terminal was fine.  So I tightened it up, the bike started just fine, and ran normally all the way home (20 mile freeway ride).  I believe that if the issue was truly the battery, the dash lights would not have come on so dimly like that.

Now, I seem to have terrible luck with Hall Sensors.  I went through two on my old k100, and have gone through one on this k100.  I wonder if this was due to a failing Hall Sensor.

Over the passed couple weeks, I noticed random very slight and instant drops in power that lasted no more than 1/4 of a second.  I figured I couldn't do anything about it till it got worse, and now I'm here!



I recall reading awhile back that the Hall Sensors are quite simple and can be made with elements that are readily available from places like Radio Shack for a few bucks, (using the BMW back plate of course).  I'd be interested in doing this instead of spending another $100 for a used Hall Sensor or $400 for a brand new one.  So, does anyone know exactly what I would need, or have a how-to on making a Hall Sensor?

Thanks in advance!

A loose battery terminal will do that.

Or a dicky ignition switch will give a momentary cut out.

Sounds nore like a power supply issue than Hall sensor. No power to restart and weak lights says it. Check the battery connections and the earth connections and as said the ignition can go faulty but check the connections first. I would check the battery too for what its worth.

I am not sure of the wisdom of turning the bike on to warm up and then leaving it running. That can also drain the battery as the alternator doesnt charge the battery when you do that so you are actually draining it to keep the engine running. If the battery is poor this can drain it quickly. It would seem to be a case of fire up and ride off.