Originally Posted by bseelbach
I had the same problem. Tried a new plug/wire and even moved the CDI behind the seat post. The only solution that worked was to use a magnet to reduce EMI. Most Radio Shack carry them but I had to try two stores. The barrels open to wrap the wire through the center and then snap shut. works great.
Those are not magnets but ferrite toroids. They never did anything to help the speedo problem for me. What worked was using resistor wire, moving the CDI back, and putting LC filter in the sensor line. 20 months 6500 miles now with no reset on one bike. Probably replace the battery soon.