Starter motor won't shut down....Solenoid is new and works perfect...when cold.

[Pedals]

Good morning all.
Ive got a 93 model, rides nice, very original, I love the thing.

Recently whe the bike gets hot,the stater motor kicks in while I'm riding and I cant stop it with the kill or ignition switch. First time it kept going until it blew the battery up, nasty stuff.
So I got a new battery and a new Stater solenoid. I also removed the starter and gae it a clean, it looks like new and has no real wear, works perfect.

I start and stop the bike and it all works fine while the bike is cold so I go for a spin around the block, but when the bike warms up a bit it happens again.

I caried a spanner in my pocket so I could quickle dissconect the battery on the side of the road. Battery and solenoid were saved this time. But I can work out why it's shorting? or is there something else happening? Theres no short in the wiring I can find.

Anyone have any experience with this type of thing before?
The starter solenoid is the correct one but it's so cheap, could that be the problem?

Cheers

Gabe "Pedals" Parker
Brisbane Queensland

[Pat Conlon]

Assuming your start button switch is clean and checks out (make sure it pops back out) it sounds like you've got a ground fault in the starter relay control wire. The start button grounds the circuit and energizes the relay. Look in the back of your owners manual and you will get the color code of the relay control wire....follow that wire to your handle bar start button. You have a scuffed wire that's intermittently going to ground. Look around the steering neck area. Wires commonly get scuffed insulation from rubbing against the grounded frame.

Let us know what you find.

In our Electrical Files there is a very nice current flow diagram (sheet 1) that may help clarify things for you

Thanks to CutterBill: https://fjowners.com/index.php?topic=18991.0

Cheers.  Pat

[red]

Pedals,

Attach one of the battery cables to the battery with a heavy clamp, not a bolt, for troubleshooting.  Engage Neutral gear, and use the center-stand.   As you move various wires, the fault may re-assert itself at any time; the clamp makes it easy and quick to disconnect power and kill the starter.

If you find the problem area, use strong electrical tape to insulate the worn wiring, and also apply tape to insulate the metal frame where the worn wires were touching ground.

Happy hunting . . .

[Pedals]

Ok , so the Starter solenoid is shorting, but what would cause such a thing? is there a better quality one perhaps?
Thanks for those testing tips. bike on the stand with the clamp idea is gold.

[fj1289]

Ok , so the Starter solenoid is shorting, but what would cause such a thing? is there a better quality one perhaps?
Thanks for those testing tips. bike on the stand with the clamp idea is gold.

Well, the first one lasted 30 years, I'd say that's pretty good quality.   Buy two and you'll be set until 2083 ......

[Pat Conlon]

Probably the same company that made my cheap eBay fuel pump that had a "lifetime guarantee" .

Lesson learned.