Nick Hull wrote:

In article ,
JR North wrote:



The plug is NEW, properly gapped at .030". Also tried plug gapped at
.020" and .010". Doesn't light.


Open the gap up on the plug to at least .075 and see if it sparks across
the gap.
From all the information you gave, it seems that there is no spark
inside the cylinder with compression which increases the effective gap.
By opening up the gap and looking at the plug firing you can see if
there is a breakdown inside the plug.

The old spark plug testers had a ignition coil and a way to presurize
the plug and watch the spark under high pressure to see if the plug
would break down.

A new sparkplug dropped on a hard surface is likely to be junk, it will
still look new though.


John