biking trying to start on its own!

This morning I thought someone was trying to steal my motorcycle.
1. Heard the starter kicking over, so I went into the garage.
2. Nobody in the garage, key is in the off position BUT the starter is going for broke.
3. Hit the kill switch (up and down). Did not stop the starter.
4. Turned the key on, hit kill switch, put back in run, hit starter button and released. Starter still going to town.
5. Turned it off and took the key out of the ignition. ITS THE ENERGIZER BUNNY REBORN!!!!
6. Hit the kill switch again. STILL GOING!!!
7. Cursed for a minute.
8. Started to undo the negative battery cable, but the energizer bunny finally died.
9. Checked the starter button, contacts are all good and wiring is all good.
10. Checked the wiring for the ignition switch and it is all good.

***The only work done recently is a new clutch cable. I did find that the neutral switch ground wire was disconnected.***

ANY clues as to what caused this!!!!

With the key off, there is really only one possibility, the starter relay. I've had them stick, but normally only after releasing the start button this happens when the contacts in the relay stick. I can't imagine a motorcycle sitting idle suddenly getting stuck contacts though. That's a good one.

Yep, that would be my guess too. The starter relay. Either it is stuck "on"--(unlikely without someone pushing the start button to begin with), or something has shorted the poles to close the circuit.

I don't know what bike you've got, but the relay is probably behind your left side cover. It should rubber caps covering the poles, but it sounds like something is making contact between the poles.

Thanks for the info, will check that out right now!
We do have a crap load of spiders in the garage?!

Ghostly biker?

If it does it again, call those ghost hunters that are all over the Discovery Channel. Hell, if they can make a 30 show out of a cold spot in a basement, they'll make a mini-series out of the "ghost bike".

Wow, that must have been a rush. First thinking someone was stealing the bike and then finding it trying to start itself.

Maybe it was trying to get away, have you been mistreating it???

MISTREATING!? Why I outta....

I saved this motorcycle from a life of rust! Found it sitting in a shed with only 400 miles on it. Rebuilt everything. Repainted everything. Gave it new treads, new paint, new cables, new hardware. Mistreating!

Seriously, what has not been replaced on it is 27 years old! It runs great (normally). Its a 1981 KZ750 LTD H2.

The poles of the relay have a lot of movement in them. The rubber that sits on the bottom of the poles has cracked and broken apart. Did not see any scorching or critters. The 2 screws holding the top on, can they be removed and contacts inside cleaned?

You can't help laughing when you read a post like this. I know it's not funny to you, and I know I'd be freakin' if I heard my bike's starter going in the middle of the night. I'd probably shoot my bike or myself by the time the cops & paramedics showed up.
Don't know anything about what's inside the starter relay, but it's got to be your problem. Maybe it's time for a new one?

Your starter solenoid has failed and acts like you have hit the start button.

For a much cheaper replacement, take your old solenoid with you and see the local riding lawn mower repair shops.


I told a rider about this on another forum and instead of $100 he spent $15. Sears carries parts,John Deere does too and I'd imagine the other places can find a suitable solenoid to fit. Some minor wiring will have to be done but that's cheaper than the dealership!

Yeah, they want $104.12 after tax. Going to take her apart and see if I can clean it up. Then I'll start spending money.

The return spring has probably failed allowing the starter motor to try and start the engine. If you can replace the spring with a suitable substitute great!