Oil / mixture ratio ? Johnson 5 Sea Horse

[Peter D]

I'm sure this has been answered elsewhere on this site ...However, I just got a Johnson 5 Sea Horse model #LD - 10S, ser. # C469367 at a local auction. I've run it on a 50/1 oil /gas mix but it did,nt run that good. Looking at this site, I'm wondering if I should be using a 24/1 ?? Any suggestions. Thanks

 

[Paul Moir]

Re: Oil / mixture ratio ? Johnson 5 Sea Horse

OMC changed the mixture ratio on all it's engines to 50:1 in '64, so yours is also 50:1 since it was built in '65.<br />If it's not running good, their's something wrong. Can you describe your problems?

 

[Peter D]

Re: Oil / mixture ratio ? Johnson 5 Sea Horse

Paul..Thanks for the reply. It seeemed to lack power and seemed to be running on one cylinder most of the time. I pulled the plugs and confirmed that one was wet and fouled. I,ve got a spark on both plugs.

 

[Peter D]

Re: Oil / mixture ratio ? Johnson 5 Sea Horse

PS...Compression seems good on both cylinders.

 

[Paul Moir]

Re: Oil / mixture ratio ? Johnson 5 Sea Horse

I've seen a few J/E outboards like yours loose their spark at higher rpms. What happens is that the ignition coils' insulation cracks from age, and arcs over at higher rpms. If the coils have never been replaced on your engine, they are almost definitely bad. Seeing that you've got gas and compression in your bad cylinder, I'de bet this is what is wrong with yours.<br />The only decent test is to inspect them visually by pulling the flywheel. You need a 'harmonic balancer puller' from an auto tool place like Canadian Tire or Princess Auto to get it off.<br />The coils are available from a Johnson/Evinrude dealer, or you can get new ones out of the 'states for around $15 US each.<br />Search this forum for 'cracked coil' for more information.

 

[Paul Moir]

Re: Oil / mixture ratio ? Johnson 5 Sea Horse

I forgot to mention: in your search, pay attention to ignition systems on '50s to 1970 J/E outboards 40hp and under. They're all very nearly identical to yours.<br />Good luck!