spark plug failure

[imacwalker]

Has anyone seen a spark plug do this ?




this is the top section where the cap fits onto it-  I noticed a small arc hitting the cylinder from the plug cap - switched off had a look moved the cap realising that it was moving a little to much- pulled it a little and the whole inner shaft of the spark plug came free-

thinking the worse - I.e. the plug had disintegrated inside the block I decided to remove the plug- thankfully its intact at the other end-

I didn't notice any drop in power- as I have a 2 plug head so the other plug was still working - though I did notice that I wasn't burning fuel as cleanly, and had an excellent over run burble -

new plug in and I'm running sweet-

[Juvecu]

I only recall seeing that once before, I'd wager it's a rarity, but a mechanic might be able to give a more accurate opinion. Any idea how old the plug is?

[imacwalker]

6 months - fitted by the garage, I have a feeling it was the wrong temperature rating- as the set I got from the Suzuki dealer were rated higher

[greywolf]

That's a failure in the plug manufacture or, most likely, a botched installation that cracked the insulator holding that piece. The plug temperature rating is all about the end inside the combustion chamber. Too cold and deposits won't get burned off, fouling the plug. Too hot and the electrodes will erode too quickly.