[mitzygolf]

 I have problem with a Villiers MK12 fitted to a Monro tiller not getting a spark at the plug. Connected the spark tester from plug cap to earth and the light flashers beautifully. Plug cap to body of spark plug light flashers as should. Plug cap to plug terminal no light. It’s as if the spark isn’t strong enough to go through the plug. Before you ask I have used two brand new plugs. Any ideas?

[JGM]

To try and narrow it down... What kind of spark tester do you have, is it a neon or a 'gap' type? Are your points (and plug) correctly gapped and scrupulously clean? Is your condenser new (or tested)? If you connect the high tension lead to the spark plug terminal and earth the body of the spark plug, do you get any kind of spark at the plug?

[JGM]

These are for the older Mk 12.

[mitzygolf]

Hi thanks for your reply. It's a neon spark tester and there is no spark when the cap is connected to the plug and plug earthed. I'm inclined to think it's the condenser as the spark doesn't seem to have the strength to jump the plug gap and it's the only part of the ignition system I didn't replace during rebuild. I've ordered one so I'll let you know how I get on. Thanks

[JGM]

Good idea to replace the condenser. Be aware they may store a significant charge if you have tried to start the machine recently (especially if faulty). Connect the wire end to earth to discharge it. Good luck.

[mitzygolf]

Hi the wire from the coil to the points isn't long enough. Do have to use a specific wire or can I use a strand from normal three core cable?

[R Tallentire]

Any insulated wire will do. Many manufacturers used cloth insulation due to the heat but many didn't, and plastic coated seems to survive OK.