HELP! 76 merc 3cyl 65 hp type III ignition with no spark. this has been a very intermitent problem until now. history: installed used swich box for int. no spark, no change. carbon contact in dist cap breaks off and destroys dist and breaks belt. install new belt, used dist from boat salvage(told me it tested good), it backfired one time now I have no spark. tried old switch box, no spark. have power at red wire and white wire on box. have tried many tests (I am an auto tech by day) but cannot pinpoint. can anyone help me. thanks
