Sparkplugs?

[Mike A]

I have a 1988 110Hp Johnson OB and a 15HP Johnson kicker. I am looking for a plug that will prevent<br />fouling at lowspeeds (I run high speed out to where I fish, then troll for<br />hours, then run back in. I gave up on the stock Champions that OMC<br />recommends years ago. Fouled constantly. I have used NGK and Splitfires with<br />somewhat better results.<br /><br />I'm hearing that NGK (and others) have developed newer plugs (V-plug,<br />surface discharge, etc.) that will help or even eliminate the fouling<br />problem. I see that Liquid Sports a large variety of NGK plugs. The<br />recommended Champion plug is L77JC4. Will any of those plugs run in my motor<br />and help with fouling? Other suggestions?

 

[Joe S.]

Re: Sparkplugs?

If you do alot of trolling make sure you are running premium gas and a high quality oil such as OMC. From what I have heard from many marinas is that split-fire plugs are one of the worst plugs you can run in an outboard. I have always had good luck with NGK. They are far superior to Champions in quality. However no plug is going to prevent fouling up under excessive idling with a big outboard. You may want to concider increasing the heat range of the plug one notch. If you do this make sure that you are going to be trolling 80% of the time otherwise you could do damage to the pistons with high speed cruising and too hot a plug. Also with alot of trolling you may want to think about decarbonizing the pistons.

 

[seahorse5]

Re: Sparkplugs?

For the last 5 or 6 years, the factory recommended plug for your V4 is the hotter QL82C gapped at .030", not the QL77JC4. It's been published in the Parts and Accessory Book for years.<br /><br />Fouling can also be caused by thermostats not allowing the motor to warm up enough, carbs gummed or flooding, linkage and synchronization out of adj., and piston and cylinder condition, the use of a marginal quality oil. Many times its a combination of things.