Melted spark plug

[studders]

So I was heading back to the boat ramp and all of a sudden it sounded like something blew up. At first it sounded like I blew and exhaust bellow or something. It was still running so I lifted the hood and noticed the plug and wire was laying on the floor. It was on cylinder #1. It took me about an hour or a little over to limp back to the ramp at pretty much idle speed. What could of caused this to melt and blow out like that. It is a merceuiser 3.0 engine. Thank you

 

[alldodge]

Defect in manufacture of the spark plug

 

[studders]

Defect in manufacture of the spark plug

Thank you. I can’t remember what brand it is but I’ve alwaud used them when I changed the plugs on my boat. I haven’t really looked at yet but I should and hopefully be able to get the rest of the plug out of the hole.

 

[Bondo]

Ayuh,..... What do the other plugs look like,..??

That one looks pretty white,....

You could have detonation goin' on, creatin' localized hot spots in the cylinders,......

 

[scoflaw]

Looks like mechanical damage with the bent electrode and broken insulator

 

[alldodge]

Wouldn't be a bit surprised if it sooner or later happens to all of them. Its built by a machine and sometimes things just don't go together like it should. No matter what plug it is I wouldn't stop using them just to find one, I would need to find several

 

[Scott Danforth]

could also be that the plug was not tight and couldnt transfer heat to the head.