T.Toad.

If, when you turn on the ignition, you get a spark but none after the first one then the Hall senor has been done in. They can be replaced but some are rather difficult to do depending on how they are mounted above the crank hub. If you have one that's a bit more than you care to try just send it to CH Ignitions or Ralph Cunningham at RC Ignitions. Don't feel too bad since many have done the same before you.

If you have a CH Ignition that has a separate ground strap the the plug wire has to be connected to the plug and the plug grounded to the engine to safely trigger the Hall sensor and ignition. Otherwise you have what happened to you. The ignition instructions note what needs to be done with the ground strap but there are better methods of attaching the ground. I prefer to attach the ground directly to the top of the engine cylinder with an 8-32 screw and nut similar to the manner Brison used to do it. The reason is that all too often the ground can be broken by vibration when the engine is running, causing rfi. It's worse when you attach the ground to an engine mount bolt.

Check with Terry or Bill at CH and I'm reasonably certain that they will concur with the attachment method. The reason it's not often suggested is that many are afraid to drill a small hole in the top cylinder fin, and manufacturers know that sooner or later someone would manage to drill a hole all the way into the combustion chamber by not paying attentin to where they were drilling, and of course blame the ignition manufacturer for providing inadequate drilling info.