Does anyone know what torque specification Champion used when assembling two piece base plugs at the factory. Steve Jelf and I would like to know.
All i have ever read, was not overly tight, as they expand when they come up to temp.
This is from my copy of the 1917 Dykes manual. Notice the recommendation to clamp the bushing in a vise and turn the base of the spark plug when tightening :
Here is the advise on torque - start with less, and if necessary you can tighten a little more if it leaks in use: