In the shop, I have a vintage Garden Way Troy-bilt beast. I performed a valve job and valve lapping (the exhaust valve was not closing, no power or idle), and the machine is in excellent condition, and the owner wants to restore anything and everything to get another 20 years out of it. Anyway, he had an old, rusted J8c plug in it, so I installed a J19LM, and it will not produce a spark with that plug or any others I have laying around the floor. I installed a new J8c and a brilliant blue spark...what is the deal?
No points, simple snow king coil with a kill wire and the plug wire. I did use the J19LM non-resistor as well as several other plugs. The only one that produced a spark was an NGK bpr6es and the J8C. I also tried an H10C which is used in Kohler K's and nada. Weird.