SINCE GETTING THE BIKE SOME MONTHS AGO THE REV COUNTER HAS NEVER WORKED. I HAD THE OPPORTUNITY TO SWAP IT WITH ANOTHER YESTERDAY HOWEVER STILL NOTHING.

ANYONE GOT ANY SUGGESTIONS AS TO WHAT IT MAY BE?

THANKS.

Is the earth wire bolted to the back??

Yea checked that Cammo still nothing. Cheers.

There are only 3 inputs into the tacho: earth (bolted onto the back), positive (black/brown wire) and rev signal (yellow/green wire).

Try bypassing the loom with some makeshift wire extensions (e.g. alligator clips): hook the brown/black wire that goes into the tacho straight up to the battery positive, hook the earth wire up to the battery negative (or a good ground), and hook the signal wire into the yellow/green cdi wire. Try to hook all of these up very close to the tacho so that you will eliminate any wire breaks in the loom.

It could just be a simple break in a wire in your loom, until you bypass all the wires one by one (process of elimination) you can't tell. It does happen in old brittle wiring. If you find a fault just wire the tacho around it (or pull the loom apart!).

My money would be on a broken wire in the loom if you've tried replacing the tacho with a different one.

in my case, the culprit was coming from the CDI itself because when i replace with another CDI, the tacho just work.