Re: 1981 35hp Johnson Seahorse
k..logic..the power coil provides its voltage to the powerpack...the trigger < or sensor > provides its voltage to the powerpack..if either of these isn't functioning you'd have no spark at either cylinder..you have spark..neither of those < with the exception of a bare spot on a wire or an internal break within the wire > can provide voltage to the powerpack for only 1 cylinder. The powerpack acts as a storage/switching unit, receiving primary voltage from the power coil and the switching voltage from the trigger. The circuits within the powerpack if defective in some way are capable of providing voltage to only 1 coil and not the other. Swap the coils < not just the wires > does the spark follow the coil? If so, then just replace the coil that doesn't spark. If not, then the circuit through the pp for that coil's position is bad and the pp will need to be replaced.
As to odds of pp vs. ignition coil failure..I don't know. The odds of your problem being under the flywheel when you have spark to one plug are pretty small.
The correct route to go is using a mm with a dva adapter < or mm with dva capability > and follow the troubleshooting chart at cdielectronics.com/troubleshooting. I believe the first test is to make certain you have no voltage feeding back into the pp from the off or grounding switch as this can quickly kill your pp.
k..logic..the power coil provides its voltage to the powerpack...the trigger < or sensor > provides its voltage to the powerpack..if either of these isn't functioning you'd have no spark at either cylinder..you have spark..neither of those < with the exception of a bare spot on a wire or an internal break within the wire > can provide voltage to the powerpack for only 1 cylinder. The powerpack acts as a storage/switching unit, receiving primary voltage from the power coil and the switching voltage from the trigger. The circuits within the powerpack if defective in some way are capable of providing voltage to only 1 coil and not the other. Swap the coils < not just the wires > does the spark follow the coil? If so, then just replace the coil that doesn't spark. If not, then the circuit through the pp for that coil's position is bad and the pp will need to be replaced.
As to odds of pp vs. ignition coil failure..I don't know. The odds of your problem being under the flywheel when you have spark to one plug are pretty small.
The correct route to go is using a mm with a dva adapter < or mm with dva capability > and follow the troubleshooting chart at cdielectronics.com/troubleshooting. I believe the first test is to make certain you have no voltage feeding back into the pp from the off or grounding switch as this can quickly kill your pp.