Ignition Issue

[MJinCO]

I'm new to the motorcycle engines. The motor is a Kawasaki KZ1000J(1982) it has a transistor type ignition system, I believe otherwise basically stock. I need new coils(they appear to be original) as the spark is very weak. The book call for coils with a primary resistance of 1.8 to 2.8 ohms. There is no mention in my book of a ballast resistor. Most of the replacements are in the 3-4 ohm range will the work with this type of ignition?

[Rick Kirchner]

ballast resistors are usually used because cars have to start in really cold conditions. I don't know about bikes, but I doubt people expect them to start at 0 degrees.

[MJinCO]

I guess the real question is: Will the increase in primary resistance have a damaging effect on the transistorized ignition?

[Rick Kirchner]

From a resistance standpoint, I can't see why. A higher resistance would limit current through the output driver. But thats only half of the equation.

How does the reactance of the two devices compare?

Without access to the actual schematic and a good EE to evaluate it, I think all you can do is put together a test setup on the bench and measure the current and voltage at the connection between the ignition and the coil, and compare to the original parts, and it will still be a judgement call.

Or, go to a Kawasaki race shop, and perhaps you'll find some old timer that once worked on the things.

[E1pix]

Knowing your location Michael, you might call the MRA (Mountain Roadracing Association) to find someone racing a Kawi in local/regional Superbike. They’d know all about this.