Katana 750 starter circuit/solenoid testing....out of the bike

I have a 2000 Katana GSX750-F that I picked up over a year ago. The seller told me that he burned out the starter trying to start it with gummed up carbs (the carbs were leaky and I believed him).



Found a used starter online, bought it, tested it, and then the project sat. I finally got around to swapping it and found out I ordered the starter for an earlier model. Doh!

Ordered the correct starter. Tested and installed it today. Just for shits and giggles, I tested the starter I removed and it worked! It also looked to be an aftermarket replacement, not the original Denso (which is what I installed today).



I now suspect the solenoid, maybe? Or did he simply run the battery flat and think he killed the starter? Anyway, the engine is out and on the bench. Carbs, exhaust and spark plugs out. I know it turns over fine by hand.

Wiring harness is in a box. I tried just going to the POS and NEG posts on a spare battery I have and the solenoid didn't do anything. I pulled the 30A fuse and it looks good. The manual has a test procedure that I need to study a little more, but it assumes the bike is complete and there's a battery in the circuit. The power to the starter seems to run through the start button, through the clutch safety switch and then to the starter motor.



Am I dead in the water as far as testing the solenoid, etc, until I get the bike back together? I tried using my battery on the starter that I installed today after I put it in the engine, but it looks like it needs to get ground to start. I can do that with the starter in my hand and the spare battery, bt not sure how to do it now that the starter is in the engine. (The new/old starter DOES test good and turn over out of the bike).



I now suspect that he either fried the solenoid, starter button or simply ran the battery dead. But I don't know how to do any further testing with the engine and wiring harness out of the bike and separated from each other, at the moment.

If you're OK with temporarily bypassing a few things, it shouldn't be too hard to test.

You'll need a thick cable going from battery negative to the frame or engine mount.

Then another thick cable to the solenoid, followed by the final thick cable from the solenoid to the starter motor.

Now, depending on your solenoid, there will be one or two loose wires or perhaps four male spade connectors. Please let me know which type you have and we'll take it from there.

Be careful of wiring the starter with it in your hand. When it connects, there's a huge torque reaction which will yank it right out of your hands. It should have a kick like a mule.

The solenoid you can test on its own on the bench with any reasonable gauge wire to activate it. It's just a heavy duty relay.