Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

[Virgil2U]

I am trying to find spark plugs for a old 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor. I have seen where spark plugs champ J6C and champ RJ6C, hotter plug (e3) Spark Plug B6S - NGK have been listed as the plugs for the motor but when I had checked out a catalog at Walmart it lists Champion j8j as the plug for the motor so I am really confused as to which plug to get. I have tried googling for a plug for that motor but all of the places I can find do not carry stock that far back. I know so people will say to look at the current plugs but when I got the motor their were no plugs in it. All attempts to contact the person I had bought the motor from have failed to find out that way. I do not live any where near to a boating store where I live to find out what type of plug to get which is odd since I live only 15 miles from the Ohio river and next to the Eastfork State Park. I was told at the bait shop their use too be boat stores and the like years ago but all have now closed up shop.

 

[Virgil2U]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

Now I have been told another spark plug for my motor. A champion J6J is the one for my motor and that I should stick to the champion brand only but this is a hard brand to come by and also plug of this manufacturer in my area for some reason.

 

[1946Zephyr]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

I would stick to the J6C in all the motors of that model year.

 

[boobie]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

Agree + 1........

 

[Daviet]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

Agree + 2, I get them at my local auto parts store.

 

[Virgil2U]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

Thanks for all the help felllows, I will check out the stores tomorrow after I wake up. I do know that the C part stands for copper which is suppose to be best for water use.

 

[Virgil2U]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

Thanks to another member here on this site I was able to get a service manual for my boat but in it the recommended spark plug is Champion J4J, another plug that I had never heard of while doing the research on the motor. I was able to track down some J6C plugs at a local O'Reilly auto parts store. I will still do more research on the difference of the plugs J4J and J6C. Also is a CJ6 the same is the J6C?

Thanks so much.

 

[lindy46]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

CJ6 is not the same. They don't make the J4J or J6J anymore. The J6C is a little hotter than the J4C and is best for the smaller engines designed for trolling, or lower speeds. They don't foul out as easily.

 

[Virgil2U]

Re: Which spark plug for 1957 Johnson Sea Horse 7.5hp AD-11 outboard motor?

OK, I will stick with the J6C plug then and thanks for all the help.