loss of spark on port side

[CCSGB]

Hey
I need help. I have lost spark on my 1993 200hp on the port side. All three plugs have no spark. The engine only has one CDI unit.. could it effect just one side? Or is there something else that may have caused this loss of power? thanks for the help

[boats.net]

Disconnect white wire from CDI to make sure it is not a stop circuit problem. Test the low speed charge coil as per service manual. If they are ok then the CDI is bad.

[CCSGB]

Thanks
low speed coil checked out OK. If white indicated problem what would you suggest be my next step? Is there more to the stop circuit then kill switch? If this was bad wouldn't all cylinders go down? thanks

[Ken]

CCSGB,
I would suspect the pulser coil of the stator - that's where the timing for each spark plug comes from, I believe. Get yourself a Yamaha shop manual and there are tests in there to check all three coils (lighting, charge, and pulser) of the stator.
If the stator coils check out ok, then I would suspect CDI.
Good luck [img]smile.gif[/img] ,
Ken K