MZ/MuZ Riders

Okay, last year when I bought this bike, I posted a question on why my bike wont shut off with either the key or the switch. I was looking at the service manual and in the troubleshooting section and there is a reference to the interference suppression unit as a possible cause for this.

What does this thing do? I can shut off the motor by grounding the black/white coming out of the ign box. I'd like to find some way to bypass this thing if it is the problem.

the black/white is connected to the ign box
the solid brown is grounded
and the brown/white goes off to the wiring harness and is linked to the switches (I'm pretty sure)

Thanks, Ryan

I never knew what that module was called. It doesn't show up on my German schematic, but I have one on both my Silver Stars. Maybe it was for the exports only? Anyhow, the BRN/WHT wire does go back to the ignition switch. When the key is in the OFF position, the BRN/WHT wire is shorted to ground. The BRN/WHT wire is also tied thru a bullet splice to the BLK/WHT wire that goes to the ignition CDI module. That's how the ignition switch when turned OFF kills the engine. Splicing the BLK/WHT and BRN/WHT wires together before they go into the "interference suppression unit" as in the pic below would bypass it. I haven't tried it though. It's name makes sense though as I suspect it's just an capacitor RF filter network that shorts RF interference to ground. And it looks like an add-on kluge unit.



When I first got my Silvy, the seller said that occasionally it wouldn't shut off with the key. It never did that for me though. I went thru all the splice connectors, cleaned them up and/or redid them. Look for a single wire bullet splice where the BLK/WHT and BRN/WHT meet. A bad connection there would cause the symptoms you are having. Also make sure all the BRN wire ground connections under the seat are making good contact with the frame. HTH -Don

More information on the interference suppression unit from the German MZ forum:

http://mz-forum.com/viewtopic.php?f=100&t=40365

Pics:









Like I suspected it's an add-on and was not installed originally from the factory. -Don