1955 johnson sea horse 5.5hp

[smyers1115]

hi everyone, this motor was running perfect my last fishing trip and suddenly seemed to lose a cylinder. cylinder tries to fire at times. the coils have been replaced and seems to have good spark on both cylinders. compression is also good. puuled carb and cleaned all but under the cap. seems to fire both cylinders when revved in tank, but returns to missing at slower speeds. please help, boys want to go fishing again.

 

[ezeke]

Re: 1955 johnson sea horse 5.5hp

The following is the best link I found on-line for the 5.5 ignition tune-up. Maybe reading through it will suggest something that was missed:

http://outboard-boat-motor-repair.c... 5.5 HP 1954-1964 Ignition System Tune-up.htm

 

[R.Johnson]

Re: 1955 johnson sea horse 5.5hp

Faulty coil, condenser, dirty points, plug wire going to ground, bad plug.

 

[smyers1115]

Re: 1955 johnson sea horse 5.5hp

thanks all, after a little more digging i did find weak or no spark on top cylinder. guy before me installed new coil, condenser, and points, but it has original wires. will start their if all else looks ok.

 

[BruceAML]

Re: 1955 johnson sea horse 5.5hp

Did you check the spark plugs? Correct spark plug, correct gap and torqued properly. Spark plug wire can be checked with a multimeter using the OHMS setting. A bad coil would be my guess as to the problem.

 

[steve66]

Re: 1955 johnson sea horse 5.5hp

I had the same problem on a 4hp evinrude,it turned out to be wrongly gapped contact breakers.
Steve

 

[smyers1115]

Re: 1955 johnson sea horse 5.5hp

changed plug wires and have spark on both cylinders. im starting to lean towards a cylinder head gasket. i also have a 10hp sames year that had a similar problem. found it in a barn seized from bad storage. decided to put new gaskets in a finish rebuild so that i can use it. purrs like a kitten and ready for the fish. boys cant wait. thanks for the replies.