Re: 1960-70 Johnson Seahorse 10
Try pumping the primer bulb and see if you can't keep it running. Perhaps there's an air leak in the fuel line.<br /><br />Plugs are Champion J4C (replaces J4J) gapped at .030". But I doubt that's your problem, not if it only runs for 10 seconds.<br /><br />Unless you can see up into the minuscule idle passages, you can't confirm that the carb is clean. Hold it suspect.<br /><br />Good spark is one that will jump 3/8". The most common ignition problem with these engines will allow the spark to jump .030" just fine, but not 3/8".