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Ihave a problem starting my scooter, there is an intermittent spark that doesn't seem to spark all the time. It often sparks through a ht lead with no cap but when you put the cap and spark plug on there is no spark at all, we've tried a cap lead and plug from a working scooter but all to no avail !!!!! What else could it be, please help,

Thanks Nigel

you haven't said what make and model scooter you are referring to and what kind of ignition system you have fitted so we are rather limited .

Have you tried pulling the green alternator wire out of the junction box and checking if you get a spark from the green alternator ignition wire to chassis earth when you kick the engine over ?
if you get a spark then the alternator ignition coil is probably ok. Next trace the Green wire from the junction box to the coil or CDI box or rectifier (depending on which model you have) and make sure the green wire is not cut or trapped or shorting anywhere. Check your connections are clean

Remove and clean your earth strap

After that its difficult to help further without knowing more about your scooters specs

Hi Thanks for That. Yes its an sx200 running on the original 6v wiring. Its gets a spark at the green wire and at the HT lead. I will double check the earth leads. Please let me know if you think of anything else.

Check the points are clean not pitted and gapped correctly between 14-18 thou.

Use a multi meter set to Ohms connect on the green from the stator and open and close the points (just slowly turn the flywheel) you want to see readings of around 0.1 ohm or less points closed and not really much higher than 0.8 Ohms points open and no less than 0.7 Ohms points open.
Closed 0.1 or less
Open 0.7 -0.8.

This just tells you that the lt coil impedence is about right and the points are earthing as they should.

Good luck.

Thanks very much I'll give it a go