Hi guys, scooter ran fine yesterday, (gy6 qmi152) warmed it up then dropped it off the main stand and it cut out. Cranked over fine but would'nt start back up. Fuel is getting through and I can smell gas through the tail pipe. Pulled the plug and checked for spark, there is'nt one! Changed out CDI and coil, still won't start. Did a continuity check on the black/white wire to the CDI, o.k. Turned on ignition and still have continuity, turned kill switch to 'not run' and same thing. What could cause the continuity to stay the same with the ignition turned on? Faulty ignition switch?
I'm gonna now check the switch and do some other tests like the stator and other wiring, kill switch, side stand kill switch wiring (though that switch was removed a long time ago)
Could there be other things to look for? As it happened when I pushed off the stand I'm thinking the impact has dislodged something somewhere.
Any help will be greatly appreciated, I really need to get it running, cheers guys, Mike
Tested stator, 133 vAC from red/black wire, 1 vAC from blue yellow wire. Unplugged ignition switch and have continuity from black/white wire. turn switch on and the circuit is broken. With it plugged into the harness there is continuity with with the key in the on and off position. Unplugged kill switch on handlebar, no circuit in the 'run' position, continuity in the 'not run' position.
I guess that leaves me stripping down the harness and tracing the black/white wire to see if it's shorted somewhere
Forgot to add, all lights and controls work. The funny thing I noticed this morning when first trying to start it again is the 2 lights on the instrument cluster that flash with the direction indicators came on briefly!
sprocket, that's what I thought. Here goes with the rest of todays shinanigans. Sitting comfortably? I stripped all the panels off back to the frame and took the floor board off so I could easily get to the harness. Exposed the black/white wire all the way from the kill switch right upto the CDI. No evidence of any shorts anywhere on any wires! Kill switch appears to work as it should, open or closed. Ignition switch appears to work as it should when disconnected. Again tried the spare CDI that I have and still getting the same continuity problem. Then I thought, and this is the real killer, unplug the black/white wire from the CDI and try the probe on the side where it plugs into the CDI. No problem with continuity, turn off the ignition switch and the circuit is broken Looks like I have 2 bad CDI's. What are the odds If only I had thought of checking with it unplugged in the first place, I would'nt have a scoot in bits with an unwrapped harness Live and learn I suppose. So after all that it now looks like I do need a new CDI. I'll order one and hope that will be the cure.
Buford, kickstand switch is long gone, removed it a long time ago so as not to have any problems from it.
Sprocket, when you say test the kill switch, how do you mean? I removed the switch and used a circuit tester and it works as a switch should, contact or no contact. If the switch is removed, is it not as though the switch is there and in the 'run' position. When the switch is on the scoot and in the 'not run' position it's basically joining the 2 wires on the back of it together creating the ground? If the ignition switch and/or kill switch were bad, would I not get the same reading from a circuit test if the black/white wire was connected or disconnected from the CDI (if that makes sense?)
Electric circuits give me a head ache trying to figure them out
Got a new CDI coming, will most likely only know for sure once that is here.
Nearly forgot, if there was a bad ground somewhere would that not cause other problems? like head lights going dim when the brake lever is pulled. I had everything turned on, lights, emergency flashers, brake light....and when I pressed the horn button no lights dimmed or anything! The 2 green arrow lights on the instrument cluster has me stumped, they've never done that before or since!! Got me thinking now, I took the muffs of the handle bars today and the left one is very close to the emergency flasher switch, maybe it was too close and had the switch in an almost on position.
The way the kill switch works is , it simply makes a connection between the B&W wire and ground. This shorts the CDI and kills the engine...
It does not matter if the B&W wire was connected to the CDI or not as long as the switch is open (no ground). Often these switches fail in the closed position, so as long as the B&W wire is attached to the CDI the engine will not run...
That is why I suggested removing the wire from the CDI, in the event that it was always closed. (grounded)
Last Edit: Apr 25, 2011 17:41:03 GMT -6 by sprocket