picture of my last break down never saw this before...
 

I was running 3200 rpm, it went POW! THEN A NOISE FOLLOWING THE BEAT OF THE RPM... Thought it was in the valve train. Came back on second engine for 10 minutes, then stalled like if I was out of gas... New fuel gauge installed the same week showed almost 3/4. Coast guard towed me back.

Turns out it was only a spark plug problem that popped off his metal part (see picture). heat burned the spark plug wire.
Changed spark plug and wire.

Opened fuel tank to see if reading in dash was good or not. NO GAS AT ALL!!! filled 10 gal of gas, both started right up, run fine now... Ho what a great day it was on the water being towed for 2 so small and ridiculous problems...

Re: picture of my last break down never saw this before...
 

wow . . . glad to hear it was just a minor prob. wonder what would cause a plug to let go like that

Re: picture of my last break down never saw this before...
 

everybody I talked to (even a lot more experienced than me in mecanic), nobody ever saw or heard about a spark plug poping off his base... amazing is'nt it ?

Re: picture of my last break down never saw this before...
 

Watch that plug carefully when you run it some more. You may be leaning out in that cylinder and causing detonation. This will blow a plug center out in some cases. Or it might have happened by leaning out as you were running out of gas to that engine.

Re: picture of my last break down never saw this before...
 

We were down in the Ozarks a month ago and a friend of mine with 500hp's in a 42 Fountain had the same thing happen to his spark plug. It was an NGK, We put a new plug and wire in and the boat ran fine for a few hours then the valve stem broke and dropped the valve but it never came out of the guide beat the crap out of the piston. I would watch it. Heat cases that to happen you may have a sticky valve or something causing a lean condition.
Good luck

Mark

Re: picture of my last break down never saw this before...
 

I ve seen the same thing also

Re: picture of my last break down never saw this before...
 

Same thing happened to me............

Re: picture of my last break down never saw this before...
 

Me Too
MINE EJECTED THE PLUG AT 1800RPM

Re: picture of my last break down never saw this before...
 

I've had that happen 4 times in a row all with in an hours time!!! they were all Champion plugs on my jetski's.....switched back to NGK and never problem again...i don't know why but it was weird...just picked up 2 pairs or champion cause they were on sale at Wally Mart at the time....lesson learned

Re: picture of my last break down never saw this before...
 

NGK Baby