Engine won't shut off w/ key?

[shaka]

Just wondering if anyone knows off hand where the grounding point occurs to shut the engine off with the key? The kill switch works fine, but the scoot (Peace Sports 50cc) will no longer shut off by turning the key off. Turning the key just shuts off the battery powered accessories, and not the engine. I did notice that there are 2 ground wires coming from the ignition, but the plug connector only connects one of the 2 grounds. This was the way it was always connected when it worked, but just to check I pulled the pin out and switched it to connect the other ground wire from the ignition with no change. Any insight is appreciated, thanks!

[Beachy]

I have the same scoot, and I just realized yesterday my key doesn't kill the engine either. I've always been a proponent for kill switches for previous motorcycles, so it doesn't really bother me, but it does seem odd.

Interesting to hear if others have that problem...

[D-cat]

Normally when you turn the key off, the black/white wire connects to the green wire, grounding the ignition and shutting off the motor. The kill switch does the same thing.

You may have a loosened wire in the connector or the strike plate has worn out. Sometimes, if your harness is wired for an alarm/remote start, instead of the black/w you'll have something a little different (brown/w). This is so the remote start can disconnect the key kill. If you have recently removed an anti-theft device, the black/w and brown/w need to be jumpered for normal kill operation when you turn the key off. Even if you haven't removed such a device, you can check under the nose to see if this jumper exists and is secure (assuming your wiring harness supports it).

[Beachy]

Makes sense D-Cat, I did remove the anti-theft on mine. I don't think I'll change it, I prefer the kill switch. Unless I have a boring weekend, which I doubt will happen anytime soon.

[mainepeace]

I have a Peace Sports 50 and I mentioned this a few weeks ago. Other posters thought I was crazy and only was hearing the sound of the engine "air pulsing" as the crankshaft continued to turn sucking air through the system (but not combusting) as I was coasting down a hill. For me, the kill switch didn't work while I was going 25+ but it would work when I was going under 10. Still happens. I just don't try to turn off the engine if I'm not moving anymore.

Greg

[shaka]

Thanks for the replies! I'll check into those wires D-Cat. The scoot doesn't have an alarm, but it looked like there was a couple extra plugs in the harness for one. The customer said that the key turned off the engine when the scoot was new. Someone stole the scooter and it hasn't worked since. It doesn't appear that any of the wiring had been messed with though. The scoot is still relatively new with less than 500 miles on it so all the connections appeared good and clean still. This gives me some direction as far as trouble-shooting goes though, thanks!

Ps. I used to own a Vento Triton and I removed the alarm system and the key wouldn't shut off the engine either. Now I know why! : )

[rapidjim]

The black and white wire from both the kill switch and ignition switch go the the CDI. As D-cat said it applies a ground to that wire hense killing the ignition. If the kill switch works, I would suspect a bad ignition switch or broken wire, black and white to cdi, green to chassis ground.

Jim

[shaka]

The kill switch works, just not the ignition shut off. Could the ignition be messed up inside? All the wires coming out of the back of the ignition look fine, all soldering points looked good.

[D-cat]

@mainpeace
That's called dieseling. I've never seen it in a small engine, only in cars (usually bigger engines, like trucks). It's supposedly not related to compression (despite these being high compression engines) but rather from your engine running too hot to start with. Any chance you're running a tad lean, or the cooling fan is not pushing sufficient air flow? Maybe it's the plug glowing hot? Anyway, if you're certain fuel is igniting, it would appear your engine is producing heat faster than it can dissipate (unless it is the plug); I'd check into the cause of that.

shaka
Yes, the strike plate inside the key ignition switch could be worn and not making clean contact. It is on the list of possibilities, especially if your harness doesn't support a remote start/anti theft device. If it does however, that jumper is more likely the cause, or possibly some other broken wire is to blame. You'll just have to look under the nose. If the problem is not self evident, than you may need to get a wiring diagram and the multi-tester out and see if you can track the problem.

[djeeper]

what if his clutch is still engaged at the higher speeds (centrifugal forces) causing his engine to still be engaged to the rear wheel?

mine will do this until about 10 mph as well (i tried it because i thought i remember it happening).

the rear clutch is still spinning fast enough to throw the pads to the bell and engage the whole driveline

[D-cat]

The clutch will probably remain engaged even lower than 10 mph (unless you use heavy springs). However, there is usually an audible difference when you turn that key to off when you're still running; the engine becomes quieter and duller though you still hear the air being pumped through. If you hear no real difference and are not experiencing the kind of drag you expect from a motor with no ignition, you may well still be igniting even without spark.

I'm not him, I'm not there, so I don't know; it all just postulating. Greg does strike me as intelligent and experienced enough to know the difference, so I'm willing to trust his assessment of what he's hearing.