Reply To: Had very interesting Spark plug Failure, maybe this info could help others

Home Forums General Discussion Had very interesting Spark plug Failure, maybe this info could help others Reply To: Had very interesting Spark plug Failure, maybe this info could help others

#16177
Bill G__

That looks bad, difficult to tell much but it sort of looks like the spark plug was not properly tightened so backed out  during use.

Once they come loose then  the spark plug heat transfer path to the cylinder head is compromised so the spark plug overheats, electrodes start to glow and erode, then pre-ignition sets in under engine load.

Looks like that one pulled the top threads out of the alloy cylinder head on it way to freedom.

What does the piston top look like? With the spark plug looking like that the piston top might look like the surface of the moon. I have seen similar in automotive engines where the  piston top ring land was actually crushed down tight onto the top ring preventing proper ring function.

If they need to remove the cylinder head post some pictures of the  piston top and combustion chamber.