I noticed the screw-in insert in the plug cap of my 360A was loose so I unscrewed it to inspect it and the cap before tightening it. This is the brass colored insert that makes the electrical connection to the spark plug. The back side of the insert was black with what looks like carbon. I'm thinking this is from arcing but not sure if it is only because it was loose or if there are parts missing that go behind it.

I recall some resistor caps having a small spring and a round, disk shaped resistor that was held in place by this insert. I'm not sure if that is the case with this one.

Anyone know details of this cap or where I may find details? It is a stock CDI ignition.

I checked Partzilla and the replacement part would be a cap assembly ... for $27.48. And it is a different style cap.

I checked the NGK site and one must specify the resistance desired. I'll dig into the service manual tonight to see if a resistance is specified.

Turns out the cap was complete. The ceramic resistor and spring were bonded by carbon to the side of the boot body. A very distinct carbon trail can be seen on one side of the resistor.

I'm guessing the carbon trail formed due to the ceramic resistor being an open circuit.

Anyone know the resistance spec for this?

I'm guessing 5K ohms

I hear some folks install a conductor in place of it. I'm not sure if that effects the CDI unit or not.

I've ordered a new 5K cap but I'm not sure it is what the factory was installing.

Looking at Partzilla, it's the same as a zillion other models... some of which I know had 5k caps.

That's a good reference.

I'll pick up a 5K cap at the local auto parts store and disect it for the resistor.

Thanks Mark!

I looked it up, zillion is a real word.