1979 johnson 15hp spark issues

[NorcalChrisCraft]

Hi, hoping to get some input on a problem I am having with my outboard.

I am pretty sure it is a 1979, it's a johnson 15hp 2 stroke. It seemed to run fine out of the water but once in the water wouldn't get me on plane. Tore into the motor and found I have no spark on one of the cylinders. I swapped the input wires to the coils and the problem follows the wire so I know it isn't the coils, plug wires or plugs.

I pulled the flywheel to see if the keyway had sheared and the timing was off but everything looks fine. There was also no corrosion under the flywheel so I cleaned everything up and reinstalled and still have the same problem.

Anyone have ideas on what I need to replace? Tying not to throw money at it blindly. Thanks!

 

[AlTn]

Re: 1979 johnson 15hp spark issues

powerpack is the most likely suspect

 

[NorcalChrisCraft]

Re: 1979 johnson 15hp spark issues

powerpack is the most likely suspect

Just grab one from, no luck....Any other ideas?

 

[AlTn]

Re: 1979 johnson 15hp spark issues

are you saying that you've installed a new powerpack and the no spark to one plug issue remains?...from the pp, the orange/blue goes to the upper cylinder, orange/green to lower, each has a distinct path through the pack. The sensor coil and power coil supply their voltages to both cylinders through the pack < if they fire one, they fire them both >. You state that you swapped the leads from the pp to the coils and the " no fire " condition follows the same colored lead. If the pp is good, a nicked wire or some internal separation within a wire is the only way I know of that one plug wire produces a spark and the other doesn't, unless you've got a bad terminal end on one plugwire?

 

[NorcalChrisCraft]

Re: 1979 johnson 15hp spark issues

are you saying that you've installed a new powerpack and the no spark to one plug issue remains?...from the pp, the orange/blue goes to the upper cylinder, orange/green to lower, each has a distinct path through the pack. The sensor coil and power coil supply their voltages to both cylinders through the pack < if they fire one, they fire them both >. You state that you swapped the leads from the pp to the coils and the " no fire " condition follows the same colored lead. If the pp is good, a nicked wire or some internal separation within a wire is the only way I know of that one plug wire produces a spark and the other doesn't, unless you've got a bad terminal end on one plugwire?

Yeah, but I just went and exchanged it for another and it now works! DOA I guess but I am good to go now. Thanks!