80 HP Mercury (S/N:5480961) 1 CYL not firing.

[sramelyk]

This may be preliminary, but..<br /><br />I have one cylinder not firing on this 80HP merc. I thought it was the coil without doing any tests and it wasn't at all.. I replace the wiring for number 3 and 4 (3 is the on not firing).. Still nothing.. I know that the stator or trigger was replaced not to long ago because the wiring harness is brand new, I just don't know which one because I haven't taken the flywheel off yet.. The harness that is new is towards the front of the motor, were as the older wires are coming out of the rear.. I talked to someone today that told me that the switchbox was probably bad.. And that part I priced at $262.. How can I go about confirming that it is the switchbox? Does anyone think it may be something else? Have I provided enough information?

 

[Merc805]

Re: 80 HP Mercury (S/N:5480961) 1 CYL not firing.

I don't think there is a way to test the Switchbox except replacing it with another working one and they are not repairable either. I would run a circuit tester (1.5v battery/globe and wire with sharp probes) across all the wires coming down from the stator and trigger to the switchbox to see if they are not corroded and broken inside. These motors (yours is a 4 cyl 1979) have wiring that is now old and a green corrosion sets in some of them. buy jabbing the casing near the flywheel and the other end of the ciruit at the switchbox you can eliminate bad wires and isolate the cause.Make sure all the coils are grounded using the same device.