I found this Powersports tach on eBay listed for single fire Harleys. It was only $59 with shipping and was listed as their Custom Mini Tach. It beat having one made up by Westach which probably would have been at least $150.

Buy the right tach to start with and this job is only four wires and a mount. I’m sure folks have mounted tachs on Changs before but I have no idea what they used. My Chang Dong has a mechanical tach so they are available.

Bend the bracket in your vice to where you want the tach.

Mount the tach. There are two screws on the tach body and I used a riser screw. Don’t forget Locktite.

Open the headlight and pick up a red power wire to a hot when the engine is on wire. The little block on my bike has all the wires to the left hot from the switch, so I picked it up there.

Black is ground and I used the headlight mount.

Blue is lights, so follow back your dash light bulb to the block. On my bike this is the block on the right.

The remaining wire is green and runs to the side of the coil that goes to the points. The only wire color I had around was blue so I extended the green with blue to the coil. I also covered the wire in all the wearing areas around the neck.

I’m not worried about accuracy as much as consistency. I just want to be able to see when I adjust the carbs when the rpm goes up and this will allow me to shift at the same point consistently. It seems about the same as the Chang Dong mechanical tach with less vibration. Keep in mind that you can usually adjust an electronic tach by adding a small resistor to the coil minus line if yours is off.