Scooterotica

Had a lovely ride out today 70+ miles, she's running sweet all the way and on the way back stopped for a well deserved pint. Country pub was shut so jumped back on and got about 50 yards and she bogged and died Checked fuel and tried to see if I had a spark, but its difficult in daylight with old eyes like mine. Phoned mate who got us back to workshop in van. Tested for spark. None. Tested LT lead to earth and good spark. Changed HT lead and tried that to earth and got weak intermittent spark, so looks like coil is breaking down. Measured resistance across LT side to E pieces and got 10 Ohms. Measured across HT to E pieces and got 8.9 K Ohms. Is that about right?

Is this points or electronic ignition?
Have you tried it with the cut out button/ignition switch wire diconnected to make sure a fault hasn't developed on this?

Still on points, I'm afraid Gonna double check it this morning and stick a new earth twixt coil and frame, instead of relying on the bolt through the E piece as the earth. The spark from the LT to earth was very good, but the spark from the HT lead to earth was very weak, and that was obviously with the ignition switch on.

Nothing wrong with points.
Try using a temporary piece of wire to connect the stator green directly to the coil positive as a fault on the cut out circuit/switch can cause these problems.
The coil I have left over from an SX150 (no makers name on it) read 5 ohms primary(+ to -) and just under 12000 ohms secondary (HT post to -), although resistance readings cannot be guaranteed to find faults on coils.

firekdp wrote:Is this points or electronic ignition?
Have you tried it with the cut out button/ignition switch wire diconnected to make sure a fault hasn't developed on this?

WHS......

spent ages checking for an intermittent fault on my series 2 of the type you describe....

turned out to ba a crap indian ignition switch...

go there first

Whipped flywheel off and the points contact had snapped off where the retaining rivet went through it. It was stuck to one of the flywheel magnets. The spark from the LT had me fooled for a while. New points in and she started second kick.