old 1950's Johnson Seahorse troubles

[pcise]

So I got swindled when I bought this(worked once when I was shown it and never worked again...) but thats ok. However, I am new to this. I can get it running if I pull on the cord for seriously an hour, varying the choke and richness. However, that is obviosuly no use to me on a lake. Any suggestions on what I should do to get it going? I dont know the model number or where to find it. The spark plugs look newish, and the motor is overall pretty clean. Ive never taken a motor apart before, so this could be interesting. Thanks tho for any ideas.

Paul

 

[Paul Moir]

Re: old 1950's Johnson Seahorse troubles

Welcome to Iboats, pcise!

Johnson made an awful lot of outboards in the '50s. I think around a million. We're going to need to narrow this model down a bit.

How many cylinders? How big? What colour? Ideally we would find the model number, which can be found in one of two places. Check the port transom clamp for a nameplate with the model number stamped into it. If no luck there, look between the two transom clamps, up on top of the steering/tilt bracket. Failing that, check the engine block down near the spark plugs for a convex silver disc, about the size of a quarter, pressed into the block.

I would begin my diagnosis with a spark and compression check notwithstanding the model. You should be able to draw sparks 1/4"-3/8" long from all plug wires. Compression should be even.

 

[F_R]

Re: old 1950's Johnson Seahorse troubles

If compression is OK, and spark is not, chances are very high that it has bad coils. Almost all Johnsons from around 1951, up into the late '60s have bad coils unless they already have been replaced. The magneto is referred to as the OMC Universal Magneto and parts are available almost everywhere. Well, speaking of USA and Canada anyway.

The magneto type with a rotating center magnet is not included in these comments, however those coils are almost bulletproof. Also, there was a magneto that was only made for a couple of years, and those coils are also always bad...and they've been unavailable for about 40 years.

 

[tashasdaddy]

Re: old 1950's Johnson Seahorse troubles

don't fret. the models in the 50's are almost bullet proof as said. find the numbers of post pictures, i run a '55 15hp rude every week. they are about as simple as working on a lawn mower, just more parts.