First Post! Starter problems

Hey guys, I have a 1981 KZ750H LTD that’s having a bit of a problem cranking. For a bit of background, I purchased her from a man in Indiana that had the starter button go bad on him, so he hot wired it and was quick starting it with a screwdriver off the solenoid. I’m not completely positive to all the changes he made as far as rerouting goes, but it did run and ride the day I picked it up. After getting it home I bought a new starter control, took it apart, cleaned all the contacts, and wired it into the harness.
After hooking a new battery to it today, I discovered that I’m not getting it to crank with the starter button. I did get it to try to crank off the solenoid, but boy did it sound unhealthy.

Is this seeming like a solenoid problem to you guys or more starter related? The bike only has 6,100 miles on it, so it’s a shock to me that the starter would be having that much of a problem unless it’s just worn from the previous owner’s quick starting. :huh:

Are you pulling in the clutch lever while you try the electric starter? Also, be sure to make sure the kill switch is working ok. Ed

I am pulling the clutch when I try to engage the switch. I just used a test light and discovered that I’m not getting a read anywhere on the kill switch. I do have two female wires that don’t have a mate, all the other lights and switches work, could these be related?

Normally the kill switch must be in the "RUN" position for the engine to even try to start. With it in the "OFF" position nothing happens when one pushes the start button. If your wiring has been modified it may bypass the kill switch. If it was my bike I would start by ensuring the wiring is in the stock configuration and ensure that the kill switch actually works. If it doesn't work I would replace it. Ed

What colour wires and where are the two female connectors. 650's have two black wires under the tank which are part of the kill switch circuit.
Download a wiring diagram and get your volt meter out.

First thoughts;

Check the solenoid’s two smaller wires for current when you’re pressing the start button.

Since it cranks when you jump the two larger posts, one way or another the solenoid isn’t switching. If your two smaller wires are connected, and you get current to one when pressing the start button, then it’s probably the solenoid that’s the issue.

If not, then somewhere the wiring has an issue and you’ll need to trace every connection back from the solenoid to see where your lack of current starts. It could be a broken wire or a faulty switch.

Notes:
-Make sure your key is in “On”, not the position past that, if your bike has one.
-If you don’t care how it looks, you can make do with a small lawnmower solenoid from Home Depot or similar.

It’s a black/yellow female ground coming off one of the battery tray bolts in the frame and a white/black female wire that seems to be coming off a relay of some sort? The picture is attached above!

There MIGHT be a difference between our 750-4s, but here’s what mine’s like - the black smaller wire goes to a 2-wire connector, then the starter lockout switch, then the stop-start switch on your handlebars. The other small wire, the yellow-red, goes to the same 2-pin connector and changes to a yellow-black ground on past that.

So, I’d start by checking for voltage at the black wire of the 2-pin connector with your clutch pulled in and your start button pressed. If yes, probably a solenoid problem. If no, it might be the lockout switch - I bypassed mine because it was broken.

EDIT: By the way, in the photo you included earlier, I believe that’s a fuse holder - my bike’s got one as well. One side in use for something (I forget) and the other not connected.

Does your bike have a side stand lock out switch? None of mine do but mine are earlier models. I know Kawasaki did adopt a side stand switch which was incorporated to stop you riding off with the side stand down.

It was fortunately way less complicated than I was making it. The plug from the kill switch was just loose enough to not make connection. Thanks guys!