What Spark Plug should look like on a 1989 Evinrude outboard SPL V-4 SPL

[Bobby Autry]

8) Good day everyone,

Does someone have a picture of a correct burning spark to use as a reference when seeing if your spark plug is burning right? Reason I ask is because I just changed my plugs out a few outings ago because my other plugs that were in the boat motor were black on the ceramic on #2 and #4 cylinder so I replaced the plugs with new ones and I am getting a light tan to light brown color and dry on all of them. I was just curios. Today was the first day I checked the plugs since a weekend ago, maybe that is why they are dry but I did see oil on the plug threads. Let me knowo

 

[Silvertip]

Re: What Spark Plug should look like on a 1989 Evinrude outboard SPL V-4 SPL

A little oil on the plug threads is normal. No concern there. The light to medium tan color indicates a fuel mixture that's perfect. If you idle or slow troll for extended periods the plugs may look fairly wet and change color slightly but a good run back to the dock at full throttle will clean them up again.

 

[WillyBWright]

Re: What Spark Plug should look like on a 1989 Evinrude outboard SPL V-4 SPL

I prefer medium to dark brown on the center electrode ceramic. The lighter, the leaner. Slightly damp looking. They may look darker and darker with more time.

Sooty black is bad, glazed black is worse and probably fouled. Surface gap sparkplugs work well if running upper RPMs most of the time. Conventional for all the rest.