Engine dying - what to check?

[fraserp200e]

The wiring does look a bit "tired"!!

I'll get the flywheel off tomorrow and have a look at the stator and wires and swing through it and the wires with a multimeter, I'll probably heat shrink all the wiring and replace the spade connectors just for good measure.

[wack 63]

The stator wires tend to go flakey as they age and the internal strands are very fine so corrode easily. I've also seen a CDI where the HT pin had rusted away causing the scoot to cut out.

[gaz_powell]

I'd second the stator wires corroding as the outer sheething goes brittle.
Had it myself - rewire sorted it.

[ArmandTanzarian]

I'd agree on the likely electrical problem. Stopping for no apparent reason and then magically working again is usually either a wire with iffy insulation, a bad joint, a bad earth or a component failing as it gets warm and then working again as it cools down again.

My Lambretta did it for a while. It would stutter a bit, then be fine for ages then not start, then work again. Eventually it died on me and I had to wait 8 hours for the AA to get me home! It turned out to be the LT coil on the stator breaking down.

[fraserp200e]

Had the flywheel off today to check stator wires and everything looks ok.

No isulation breakdown and wire continuity all ok. found a couple of crappy cable connections futher away from the stator as it goes into the junction box (bare wire twisted around each other then phase taped, white to the CDI, blue and black from the stator) so have redone all those properly. I also cut a wee bit off each end of the HT lead and checked all is good there at both ends. I'll drive it around for a bit and see if that sorted it - it started first kick and was ticking over fine.

Got another CDI and carb on standby if it's not sorted - I'll post up when I find the fault and hopefully save anyone else who gets this snag some time.

[Spreader]

I have a PX150 that did the same thing.
Driving along and it would just cut out intermittently, not like a fuel problem, but like I hit the kill switch. Checked the kill circuit, examined wires around the headset and tube, replaced CDI. None of that worked. Finally I replaced the ignition pickup on the stator (little black cube) and that did the trick.

[coaster]

My money is on the LT coil, do you have a meter that reads resistance? if so, check between earth and the Green wire from the stator. If you have less than about 450 ohms you will have found the fault, Also check the resistance of the pick up, that should read 95 ohms or more. Sometimes the earth tag on the stator can come loose and cause intermittent faults. Generally, CDI's tend to just fail and stay failed.

[fraserp200e]

It seems to have been the crappy connections on the wiring from the stator. Has been fine since I redone them. Glasgow to Whitby and back with no problems, running sweet!

Cheers for all the advice.