your gonna want to go under the quad. theer will be a wire that runs to the shifter/ speedo that connect by the engine to the rear drive shaft, and check that entire wire for any shorts, or a cut wire. if the speedo continualy read 0 than it would def be this problem, but it still may be this problem due to the shifter malfunctioning. than scheck the connection of the wire i was talking about to the main connection under the right rear fender. if that doesn't work than check the front sensor connections on the front drive shaft, along with those wires. but, like i said first check the wires that go to the rear by the engine on the drive shaft!
hope this can fix that problem. if the speedo no longer worked, than what i said would be a definite, but make sure to check anyway!

 

If your quad quits shifting only at higher speeds and has all the symptoms 250xRKrider said it’s definitely what he mentioned. He was talking about my quad and that’s exactly what happened. Quit shifting at higher speeds and didn’t display the speed. Actually I just checked in my Honda service manual and on page 1-23 and 1-29 under general information the wire is labeled as the speed sensor wire. Hope that helps.