84 ZN1100 Cylinder Head Upgrade?

Looks really good. Pay attention to the dark spots that I see on the ceramic in plugs number two and four identified from left to right. Could be an indication of preignition. On the surface they look great. Get a good light and a magnifying glass and look down inside where the ceramic is in contact with the steel and make sure you don’t have any dark or shiny spots.

wrote:

Looks really good. Pay attention to the dark spots that I see on the ceramic in plugs number two and four identified from left to right. Could be an indication of preignition. On the surface they look great. Get a good light and a magnifying glass and look down inside where the ceramic is in contact with the steel and make sure you don’t have any dark or shiny spots.



 

Got about 400 miles on the motor since the head was done, and had to change jetting to compensate for that and recent cool air temps. 
Those plugs are a few years old.  The base rings and electrodes were wire-brushed clean (but not down in and around the insulators) at about half of those miles.  She'll have new spark plugs in the Spring!
No popping, bogging or hesitation, and I am very happy to have this all wrapped up before Winter storage.