1967 johnson super seahorse

[jcalexander]

I have a 1967 johnson super seahorse that will not run at idle speeds. I have to keep it at full throttle to keep it running. I found that the spark plugs were hitting the pistons. It had NGK B7HS spark plugs. I have heard you can use champion j8c plugs but what should i do???

 

[Daviet]

Re: 1967 johnson super seahorse

Check to see if there is any play in the crank or rod bearings, if none, put the correct champion plugs in it and rotate the flywheel by hand and see if the pistons hit the plugs.

 

[kfa4303]

Re: 1967 johnson super seahorse

Hi jc. Welcome to iboats. What is the hp or model number of your motor? You should use Chamion J6C plugs for most OMC motors of that era. J8C are probably a little too hot, particularly for the smaller hp motors. NGK plugs can also be finiky and don't always convert readily to Champions. If you're lucky, all it will take is a plugs swap, if not you'll need to get into the guts of the motor to see what's wrong. Here are some great all around link for your motor too. Once wer get the exact model we can help a bit more, but these will get you started.

http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm

http://www.duckworksmagazine.com/06/columns/max/index6.htm

http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1967 (click on your engines hp and follow the links to a complete parts catalog with exploded diagrams of your motor)