My speedo has started to read low. It seems to be about right when I first get going, but gradually drops off or is very slow to respond to speed changes. I am assuming dirty connections within the instrument unit, but am after any other suggestions. Its a second hand unit that I picked up a few months back and has been good until now. Everything else seems to work.

Pull the sender out of the rear drive and check the face for iron dust accumulation. I have seen this play havoc with the speedos. It collects the tiny particles of iron from the wear of the gears and bearings.

Mine does that too. But a little tap on the clock seems to sort it for now. In my case it seems the problem is the cable connector into the clocks.

It is a known problem though and there are threads on it.

And yes the rear wheel sensor check it first.

This isn't actually a problem!

"But officer, my speedo said I was only doing xxxxkm/h."



Bill

indian036 wrote:This isn't actually a problem!

"But officer, my speedo said I was only doing xxxxkm/h."



Bill

Yes Bill, I'm sure I'd get away with that

The sensor is easy to check so I'll start there.

Mine was doing that on the naked. Advice from the forum was to clean the sensor connector at the R/H side right where the tank connector is. Worked a treat.

You should be able to get at that connection without taking the tank off. Two wires go up there on the forward facing frame member, one for rear brake switch and one for the speedo sensor and both connections need a clean from time to time.

92KK 84WW Olaf wrote:You should be able to get at that connection without taking the tank off. Two wires go up there on the forward facing frame member, one for rear brake switch and one for the speedo sensor and both connections need a clean from time to time.

Yep, know where that is. I'll start with the sensor and work forward.

I cleaned everything. Connectors, sensors etc. It is now ok up to about 110kmh but lags behind after that, but behaves normally when I slow down again to 110 or less. I'm putting it down to a dodgy sensor unless someone has a better suggestion.

last place to look is the instrument connectors ...they do get corroded on the pins sticking out of the instruments

I re-soldered mine with a definitive fix ..but sometimes the film connector inside may go partially open circuit

it isn't hard to solder in a parallel conductor pin to pin to bypass the flakey joints ...

don't forget that the odo - speedo  motor has separate pins to the film connector , which also become corroded on the contact points ...the whole assembly of the odo - speedo is easy to remove with just 2 screws ..once apart  then you can see the details of the pins and connectors

Yes I probably need to dismantle the instruments and clean all the connectors. Its a used set I got off Gumtree(?) and I just bolted them on. Everything seemed to work then. I did notice some improvement when I cleaned the sender, for what thats worth.

mine does that occasionally mate , usually its the side cover connector ... and after rain

after filing it lightly for more positive contact , and crimping the socket part a little tighter , hasnt happened again for over 3000 k  and always stable now