k100rs speedo problems

[carrickleagh]

speedo on son's 89 K is exhibiting intermitent failure, climbing slowly to 40mph max and down again. Odometer works fine. I've cleaned sender unit and connections and opened clocks and looked inside but am baffled by plethora of screws and stuff. All I can say is copper plastic thing if you know what I mean seems ok where it folds. Any suggestions would be greatly appreciated.

 

[Bonzo]

I always found it was the sender unit down at the end of the shaft drive, but youve already mentioned that.

I bet Steptoe will be able to assist though.

 

[Steptoe]

Take out the speedo sensor from the rear wheel and check that the speedo ring inside the bevel isn't loose.