Non Laverda spark plugs..never seen this before.

[paulincayman]

These came from a suzuki v6 300hp outboard. Left bank all three plugs the same. Tips burnt off and central electrode dropped into the three cyls. Extensive damage to bores and pistons. The other bank of three looking perfect. Both share same fuel source. Twin injector rails same as modern v car engines . Being told that it was water in the fuel..
Ive been looking at spark plugs for many many years ,bikes cars and boats but have never seen or heard of this before..

 

[GregT]

I've seen it - but on 2-strokes suffering from extreme detonation. Injecting water would raise the CR - possibly enough to cause detonation.

 

[chrisk]

Pssst, put them back before anyone notices, you’ve removed the fuel injectors by mistake.

Never seen that happen to spark plugs.

 

[IAG]

Are you certain LH & RH banks have same plugs? Looks like possible piston to plug contact...cylinder head replaced?

 

[wdietz186]

Seen it before, detonation and lean running along with some oil in Honda cars. Usually only one cylinder though. Must have been a bit noisy/rough as it was happening.

 

[Exmoor beast]

I’ve seen this- the centre electrode became lose/ snapped in half ( you could shake the plug and electrode would hit earth tang! ) . I’ve also seen nitro drag bikes ”fuse” a set of plugs at the end of a run.

 

[piranha-bro2]

I imagine if the centre electrode became loose and dislodged and then dropped to contact the tang there'd be a lovely short circuit to quickly vaporise both!

 

[Dellortoman]

A shorted plug wouldn't vaporise anything. Sure, there's a high voltage there, but there's not enough current to make it even slightly warm. All that would happen is that it would stop sparking.

 

[piranha-bro2]

Oh, can't i have a little bit of fun, Cam?!