by comanche91 » Fri Sep 10, 2010 5:26 pm
Found the problem, and I suspect this applies to all MZ Rotax bikes w. CDI ignition. The tach derives it's input signal from the CDI box on my 95. MZ decided to use one of those crappy squeeze-on splice connectors to connect the tach signal wire to the CDI box tach output wire. The intermittent contact inside the splice connector was causing the spastic tach. These connectors suck for all applications, but especially on a vibrating motorcycle. It's in the battery box, a brown squeeze-type splice connector sitting in there like an afterthought. The fix is to solder in a decent male/female connector and insulate it with shrink tubing.
-Don
1-3/4 1995 Silver Stars