speedo is all over the place

[kennystag]

Hi All,
I had the first ride yesterday on my 63 LI, the speedo is all over the place, when I am doing about 15mph it is right of the scale,any ides.
Cheers
Stag

[CHRIS in MARGATE]

Post it up in Scootering and tell them in the write up that it does 60 mph in 1st.

Disconnect at front wheel end. Lock inner cable in a cordless drill and run it in reverse and watch speedo. That will prove if it's the speedo or the speed drive in the front hub.

[kennystag]

Hi Chris in Margate,
Thanks for the reply, but I am having problems understanding what I should be looking for in this test.
Cheers
Stag

[Tractorman]

It could be the inner cable is not moving feely in the outer. The inner is like a spring it will, if it is restricted, build up energy and when there is enough energy to overcome the restriction the surge results in a higher speedo reading then it drops back again. That the head set off and turn the wheel and check for smooth action of the cable head. Could just be the cable needs lubricating or a build up of dirt in the outer or damage to the cable.

[CHRIS in MARGATE]

No problem.

If you connect your speedo cable to a drill that is switched to reverse then it will drive the speedo.
If you can vary the speed and leave the drill on the ground propped up on something lock the trigger on with cable tie or insulating tape and observe the speedo.
I can get mine to hold anything from 20 -60 mph without it wandering. My drill is replicating the front wheel turning.
If you do this and your speedo acts like a wiper blade then probably your speedo is worn out. Sometimes they wear where the cable fits and don't grip the cable fully. You can "fix" this by wrapping the top of the inner in silver paper or by trying to 'tun' it and lay a film of solder on it. These fixes might take up the wear. The best fix is to buy a new speedo.

If after trying the drill method the speedo operates smoothly then the wear is in your drive mechanism in the front hub.

[a.lo]

I managed to fix mine that had the "wiper" syndrome and it really was quite accurate. if you dismantle the speedo cable drives one magnet and the needle is on another one, these must not physically touch each other as that is what overrides the spring tension and sends the needle of the scale. wear usually makes the parts sloppy and touch, cannot remember the exact fix, may have switched a part out of another speedo. but if you look at the parts you will probably see what needs to be done.