oil on plugs?

[relics hunter]

I went to look at my spark plugs on my '74 mercury 115 inline 6 and noticed the lower 2 plugs have unburned oil on them is this normal or something I should be worried about? she still runs great in spite of this issue.

 

[Bosunsmate]

Re: oil on plugs?

Check they are sparking and check that oil burns off with a match ie its doesnt have water mixed in

 

[Texasmark]

Re: oil on plugs?

Running surface gap on that engine? Are the other plugs dry? Are your piston crowns on all 6 cylinders the same color?

Don't remember when Merc started using SG plugs but it's been a long time. I had them in my '88 115. SG plugs will have carbon streaks on them and are usually wet when engine shuts down. I ran the plugs on the engine mentioned for about 7 years. It ran an 18' boat just under 50 and loved 6k rpm....ran a Laser SS prop. Piston crowns being the same color tells you that you have no problem with water intrusion.

If it checks, go and have fun; don't worry about it.

Mark