SMART SPARKS

Referring to recent discussions of CX500 CDI malfunction, there is sometimes a simple failure mechanism with an effective remedy. This applies up to 1981, after which standard Kettering replaced the misbegotten multiple high voltage coils system.

If the CDI unit is encapsulated within a slightly rubbery compound (not sure if this stuff was universal), stick ohmmeter probes into the surface. If there is any conduction at all, that’s your problem. In 50 years of bikes and electronics I have never come across potting compounds becoming conductive, this was a first. And the remedy? Pick away at it gently, heat gun softens, brake cleaner spray helps slightly.

Eventually, with the aid of heat, the board can be prised away and components desoldered where necessary to access occluded gunge. When scrupulously clean, slap it back together and if functionality is restored seal with hot-melt. Needless to say a degree of finesse is required not to damage components but they are all standard items and readily replaced. Operation takes about a day – and a lot of cussed determination.

I also read about an Enfield aftermarket electronics spark failure. Simple remedy for that too, at least in one instance encountered. Problem was that the internal power transistor must have been poorly mounted to the heatsinking case and it was shorting to it. Hard epoxy, can’t deencapsulate, but mounting the unit on an insulating sheet cured that one. Drew Roberson