Why most motorcycle speedometers quit and how to fix them!

Maybe you just changed the tires on your sweet ride and the speedometer quit working or only works intermittently immediately after you got the tires changed! Here’s why it quit and how to fix it!
I made the mistake on my 1970 Honda CT90 and my 1973 Kawasaki G4TRC before I realized what was going on, but it’s about the same on almost all motorcycles!

[billwebb]

Thanks for the video and the explanation. I am working on a 1969 Honda C102 (50cc) and Speedo doesn't work. Watching your video, I removed the front wheel and sure enough, as you described, the tabs on the pinion gear were splayed out and not in the slots in the wheel. I put the pinion gear in a vise and slowly bent the tabs back to 90-degree right angles and voila, the tabs now fit in the wheel hole slots properly and the speedo worm gear works properly to drive the speedo. Thank You!

[e_s.]

I got a '81 Honda xl185 and the speedometer started whining and spinning after hitting 35mph after decades of being unused. The odometer works though, so im not sure what to do. Any ideas?