inherited this 79 cx500 from a guy who was moving said it ran. removed carbs, and cleaned thoroughly/45 min soak, replaced some broken/ worn wires. cleaned out tank. replaced thermostat, replaced battery. did get it to run, after all that, but at running temp, it shut down. rremoved carbs again, recleaned, wasnt necessary. now im looking at an electrical situation, removed and cleaned plugs, they looked ok. but as an auto mechanic i checked for spark, removed plug wire, put another plug on the end and nothing, this thing turns over fine, but it seems im not getting spark, parts are too expensive not to narrow this down, any suggestions?