Spark Plug Melting on Nissan TLDI 2011 B

[Backriverfish]

Ran the engine for the first time in a couple years, originally the plug that was in there was burnt closed, no gap in the plug. I replaced the plug with the correct spark plug that is stated on the engine. Ran the boat a couple more times and it was fine. Then I went out about a week later after changing the plugs and lost a bunch of rpms. I checked the plugs and my bottom plug was completely melted, never seen anything like it. The arm that comes off the plug was totally gone.

I will more than likely be bringing this to my dealer. Just wanted to get some info on what may have caused this.


Thanks

 

[Scott Danforth]

Are the plugs torqued?

Normally if plugs are loose, they will not transfer heat to the head and they melt

 

[Backriverfish]

Are the plugs torqued?

Normally if plugs are loose, they will not transfer heat to the head and they melt

Found out the threads for the plug are stripped. Looks like who ever put the plugs in before me screwed something up. I'm going to end up tapping the plug hole.