1954 Johnson Seahorse 5.5HP spark plugs, tune up, etc.

[diamondbro02]

I am currently in the process of bringing my '54 Seahorse 5.5HP back to working condition. It's been about 10 years since I've ran it, but I cleaned out the carb and got a new tank for it, and took it out for a run and it ran suprisingly well. However, it seemed to run much slower in gear than when idleing. I figured it is time for a tune up, so I have a couple of questions:

1. The original spark plug for the motor is a Champion J6C, but I was told to replace them with a J8C, since the quality of gas and oil has imprived since the motor was produced. Does anybody else recommend to do so or have any suggestions?

2. The spark plug wires also appear to need changing. Does anyone have a good replacement suggestion? I've read that this model requires a longer wire, so any part numbers (OEM or replacement) will be a big help.

3. Does anyone have any suggestions as to why the performance of the motor dropped from idle to in gear? I'm assuming that the points and condensors need replacing too, but just wanted some input before I pull the flywheel off.

Any other info that would be helpful would be greatly appreciated!

 

[F_R]

Re: 1954 Johnson Seahorse 5.5HP spark plugs, tune up, etc.

Stay with the J6C plugs. Fuel has nothing to do with it.

Just buy wire from a bulk roll...if you can find a place that sells it. Make sure you get the copper wire core stuff. Cars use a carbon string core which is not acceptable for outboards.

While you are replacing the wires you will have the coils off. Replace them if they are cracked!! Could be part of your performance problem. However, I am not sure I understand what you mean by slower in gear than when idleing.

When you install the coils make sure the laminated cores are aligned flush with the machined edges of the armature plate where the sit. That provides proper clearance to the flywheel magnets.

 

[diamondbro02]

Re: 1954 Johnson Seahorse 5.5HP spark plugs, tune up, etc.

Sorry about the performance confusion...

When in neutral, the motor revs very well like I remember it doing. However, when I shift into forward gear and throttle to fast, it doesn't seem to run as fast as I remember. The motor appears to be running slower than it should.