R1100S Speedometer Issues

[johnson92@msn.com]

I'm having some issues with the electronic speedo that I can't seem to pinpoint the cause.

It will work fine for a while then start bouncing all over the place, and will zero out when in heavy throttle and kinda come back to life when idling and I pull the clutch in. It seems to work consistently when I first start riding and will fail about 10-15 minutes into a ride, or sometimes not at all. I have replaced the sensor with no change.

Any suggestions would be appreciated.

Jeff

 

[pauls1150]

Symptom of the ignition pickup failing...?

 

[rocketmanli]

I don't know if your R1100S has the same final drive setup as my 2002 R1200C, but think its very similar. I had the exact symptoms you had several years ago. Stripped the sheathing off the entire wiring harness looking for an issue and found none. Send my speedometer out for testing, and it was fine. Turned out the $12.00 impulse sending wheel (BMW p/n 33 12 1 451 181) came off the post on the crown gear. It is supposed to crimped/presssed on. Sometimes it grabbed and spun, and sometimes it didn't. Took me the better part of a year to figure it out. If you open up the final drive fill plug, you'll see it in there. It should be silver and has ridges around the top circumference, like a rook or castle chess piece. Stick a pencil or screwdriver in there and see if you can turn the sending wheel. If you can, you have found the culprit. Its supposed to be tight on there. If its loose, that's your issue. Hope for your sake its something that simple. Its a rare occurrence, but I know of 2 times it happened.

Here's a few pics of mine for reference:

 

[johnson92@msn.com]

With that information some of the symptoms make more sense, like it seems to fail sooner at higher speeds and sometimes not at all if I stay under 30ish mph. Thanks! I will take a look and report back.

Jeff

 

[rocketmanli]

Should take you all of 5 minutes to poke around in there with a flashlight and something pointy. Hope that's it......

If you have the rear wheel lifted off the ground and gently rotate it, you can look in the speedo sensor hole and see the "turrets" moving past. If a screw driver stops that impulse sending wheel rotation, or if you can move the sending wheel with the rear wheel standing still, that's the problem. Whether your speedo registers 5 or 75 mph doesn't matter; that's only an indication that sometimes the impulse sending wheel is rotating at full speed with the crown gear, and sometimes its slipping off and not rotating at all. I hope that is your problem, as its the easiest to diagnose and repair of all the alternatives.

 

[johnson92@me.com]

My R1100S has a different set up pickup/sensor. It was (disabled) ABS equipped.