Fouled Plugs

What causes the insulator on the eletrode on a sparkplug to crack? This is the tip that goes inside the head!

Early detenation of plugs, timing, improper gap set, poor manufacturing. What brand plug do you have?

It was a champion, just a hairline crack, but it made motor run like crap! Replaced with Autolite and runs like a champ!!

Yup another Champion horror story. I have experienced many problems associated witht the standard plug, not sure about the truck series. I have Bosch Platnuims in my XJ, great plug, Autolites too.

Yup another Champion horror story. I have experienced many problems associated witht the standard plug, not sure about the truck series. I have Bosch Platnuims in my XJ, great plug, Autolites too.


Overtorquing them can cause that - even a slight shock to the plug! Heat range off?

When I replace plugs on an aircraft (Im an A&P) and I drop a plug (who hasnt?) even if its a few inches - the plug goes into the trash - federal law.

But champion seems to be having some quality control issues.

I guess it was a crappy design, I have always used anti seez and tighted down per recomendations, and I too s-can one that has been dropped.