speedo manic depressive

[acehosedme]

I have a '92 R100pd with a more than usual flaky speedometer. For the last 20,000 miles it has not had a steady even reading at any speed above , say 20mph.
The needle rises and falls about 10 mph all the time at any speed. This past week I noticed that I buried the needle way past where I usually hit the top speed, around 125mph. This week is has been wildly jumping all over the place, with the middle of the range about 15 mph above (my best guess) the speed I think I'm going.
What might be going belly up here? IS this a repaiable item? Also, sometimes the trip indicator does not start up after resetting.

Thanks
Bob

[donkey doctor]

Hello; I had all those symptoms a year ago, so I took it all apart and looked inside, removing the old lubricant and replacing it with lubri-plate. I found a slight mis-alignment in the odometer drum, so I just popped it back on it's centre and re-assembled it all. It is working steadily now but it still lies.

I bought a bicycle speedo and mounted it between the par risers, I had to make up a bracket to mount the pickup to the front fender mount. It has been absolutly accurate and reliable, at a cost of $24. It also has a bunch of other features thrown in for free. I use the clock and odometer feature a bit.

[acehosedme]

Has anyone taken this speedo apart AND written up the process or taken pictures?
Thanks
Bob

[38104]

Here's an article:

www.airheads.org, go to Technical Tips, go to the bottom: Speedometer repair for airheads.

[lorazepam]

sometimes a cable going bad will cause this too. as the cable frays, it will wind up and give you a high reading as it "unwinds" . Mose sure that you cable isnt fraying inside the housing.