The tachometer or rev counter tells how much speed of engine of motorcycle revolutions per minute (RPM). Common nowadays are electronic rev counters that can be installed by dealers you get them from. But for used motorcycle parts, rev counters usually come in just any wrapping without instructions or diagrams. In cases like these, you may install your rev counter with following instructions to help you.
The very first step is to move headlight away. This is a great help later on in avoiding some mistakes and will definitely help you finish faster. If you feel a little hesitant in removing your headlight, you might prefer to just let it dangle by wire. Just make sure that wire can handle your headlight's weight.
Then take side pin out of speedometer. Remove two allen screws from back of speedometer and keep all parts. I kept mine in a coffee mug and was able to account for all of them when I was putting everything back. Slide speedo canister down speedo cable with a good pair of pliers to loosen cable.
Notice two wires on back of speedo. Remove speedo. To easily remove, lubricate speedo then twist it out of rubber grommet that holds it in mounting plate.
At front of mounting plate you will see three allens. Remove allens and hold horizontal black plastic light pod on. Then remove two allens that hold mounting plate on chassis.
At back of speedo, there are two screws that will allow you to twist fitting where cable screws are on. Loosen them just enough to allow you to twist fitting as little as possible and with some resistance.