Scooterotica

HxPaul I had a similar issue. Don't know if your on kill button or key ignition. It turned out to be a poor connection on the back of the ignition switch.

Thanks. I've only got a multi meter. I know the cdi is working as I took it off my own scooter. I then put the suspect cdi on my scooter which started first go.
If I hold the green wire near an earth and kick over, there's a spark there, but seems intermittent. Could it possibly be the flywheel as I've changed everything else?

Yes, if yo have an intermittent spark
That will cause the problem
The other think to look for is proper earthing onto the stator

Tried two different stators, one brand new. Must be earthing ok as the multi meter readings are all good, and I'm using the mag housing as a contact. I'll try a flywheel. Thanks

ive had a few intermitant faults over the years, one was caused by the earth tag rivet being loose on the stator, fixed it by soldering it, next one was caused by a wire rubbing through the insulation and shorting out where it came through the hole in the mag housing, third one was a corroded terminal on the wiring loom that connected to the cdi unit.

I disconnected the green wire from the CDI (the green that goes up the loom to the headset ) so that the ignition switch was isolated and I went for a ride.On Saturday I did 42 miles without issue,on Sunday I did about another 30 miles before it started to act up.In total it did it twice before I got home,so obviously nothing's wrong with the igntion switch or the loom from the CDI.

Just an update for you guys. I changed the flywheel and it's sorted! How can a flywheel just stop working like that? The scooter has been sitting in the workshop for five months but never seen that happen before.

I personally can't see the flywheel being the cause of an intermittent fault. My money is on the stator which has LOTS of potential for intermittent faults. Loose earth tag and trapped/pinched/chaffed wires as already mentioned are all good things to check as well as the integrity of any soldered wires on the LT coil and Pickup. The other most likely problem would be the LT coil itself, I have had a couple of intermittent faults which have been down to a break in the coil winding. It would start and run fine for several days/weeks only to cut out with no warning. I eventually found it by removing the flywheel and connecting the meter on ohms. I then used a plastic screwdriver handle to tap the coil and noticed that the reading went open circuit when I tapped. Fitting a new LT coil worked on both stators. The reason for using the plastic handle is that if you use a ferrous tool it will generate a small voltage as it moves close to the coil which confuses the matter somewhat It could also be the pick up but I have never personally had a problem with one.

Scootermonkey wrote:Just an update for you guys. I changed the flywheel and it's sorted! How can a flywheel just stop working like that? The scooter has been sitting in the workshop for five months but never seen that happen before.

I refer the honourable gentleman to the answer I proffered 5 days ago.

Your suggestion was taken on board Daggs, just couldn't get hold of one til Sunday. It was all a process of elimination in the end. Flywheel was the last resort, everything else had been checked or replaced. Thanks for your comments