how to install an electronic tach on kz550 1983

hello, i have a question for you guys. i got this cool digital electronic tach for christmas and am wondering how i would install it. well really my question is if it would work. i can install it if you can. the problem is the instructions are set up for installing on a car with 4-6-8 cylinders. not a motorcycle. please let me know if it is possible. thanks. or it you need more info. by the way the bike is a 1983 kz550.

Most electronic tach's work by connecting to the primary(small wires side) of the ignition coils. The tach reads the electrical pulsations and converts them to rpm's on the display.

It should not be too hard to run wires to the coils. To reduce the chance of electrical interference, use either twisted pair shielded wires or twist up some 20 gauge pair wires(two of different colors) and cover them in heatshrink tubing.

I believe only the connection to one coil is needed for the tach to work, but check the instructions

If it is for a car with a distributor, there will only be one signal line to the tach. This is not enough for a KZ550, because it has two coils. You would need an adapter circuit so both coils can connect to the tach.

Without it, the tach will only register 1/2 of the RPMs (when set to 4 cyl).

You can buy them, or you can make them. Here is the one I made. It's very simple and cheap.

kool thanks

Have you gotten anywhere with this? If so got any pics?

Since the KZ 4cylinders are a wasted spark system, the coil fires twice as often as normal, so wouldn't that even out?

djturnz wrote:

Since the KZ 4cylinders are a wasted spark system, the coil fires twice as often as normal, so wouldn't that even out?

A KZ coil fires once every crank rotation.
That's one fire per revolution.

A 4-cylinder car with distributor fires 4 times per two revolutions.
That's two fires per revolution.

It doesn't matter how plugs the coil fires, the tach only senses one pulse every time the coil fires.
You need to add the signals from both coils on the KZ to get two fires per revolution.