I've gotta '99 Sportsman 335 and my speedometer is screwed up and can't figure out why. First i noticed that occasionally when i would put it into neutral after a ride it would start jumping around. It would go from 0 and peg out and jump around and from then on it wouldn't work right. Occasionally it would work and then stop. I took the casing off around the handel bars and followed the smaller speedo wire back to the right front wheel. Looked for cut or a pinched off wire but couldn't find where it was. Took the wheel off along with the sensor and couldn't figure out how the think worked. How does it read the speed? Off the rotor? Took the sensor off and it had a small metal car on it. Cleaned it with sandpaper along with the sensor. Did something fall off or is that it? I just can't see how the thing works. To me it acts like it had a bad connection, but i checked the plug and it was good and clean along with the wire comming off the sensor. 4wd still work, but this is really got me stumped.
Any help is appreciated.

 

I had the exact same problem,replace your speedo sensor wire,it runs from the back of the speedo head and goes to the right front tire area.It costs about 50 bucks for the part.

Bill