1976 Merc 402

[Timguy]

Hi, have no spark on one cyl. Problem happened while stored off season. Changed the switch box.....new CDI corp unit, still no spark upper cyl. Then stator tested poorly (just outside listed parameters) so replaced with new CDI corp unit......noticed old stator coating partially melted from before.....looks like one of the exciter coils got hot, but looked like it had run for awhile with melted coating. Still no spark one cyl so swapped wire between coils and got spark on the other cyl. We assume both coils ok then. What to do next? Could the old stator have damaged the new switch box before we changed out to the new stator? CDI corp. tech line suggested that could have happened. Motor is up at the lake and owner is not happy to say the least. Trigger tested ok too, at least before we changed the stator. Any other ideas? Thanks, Tim

 

[Timguy]

Re: 1976 Merc 402

Hello.....is anyone willing to take a stab at this one? C'mon where are those sharp Merc techs?

 

[Timguy]

Re: 1976 Merc 402

Tested new switch box and failed but the new stator produced 160 DVA instead of 180 on the blue lead......just wondering if thats ok? We ordered a new CDI switch box and returned the old/new one to CDI for testing. Do you think that the old stator damaged the new switch box as it showed quite low impedence on the exciter coil which had been melting. It tested outside CDI's listed parameters back in May, but the motor owner insisted it would be ok and only allowed me to replace the switch box, as we had good spark at the time we had first installed the switch box. Then, the first time he took it out the motor dropped the one cyl and then he called me to ask what went wrong? I pretty much know what happened but I would like a little advice here if I'm right or wrong.