Laser cutting to wide of kerf

It sounds like you need to check your external and your internal optics on the PRC Resonator.

Have you called the Amada Service Department or Applications about this?

might having the focal lens installed upside down cause this?

Actually, the 667 could have a Spectra 971 or 820, a PRC, or maybe even a Fanuc laser.
In any case, you should make a burn into plastic without the lens in place- either pull the front bend mirror and shoot through there, or pul the head and lens, and shoot at table level.

See what the raw beam looks like. If it is round and symmetric, that's good. If not, the resonator (laser generator) should be investigated.

Make sure the lens is intact and mounted the right way.
Look at the HeNe spot on a piece of paper- move up and down to see if it focuses to a small spot. (you can do this with head off and lens remaining in place)

The HeNe doesn't focus at the exact same height that the CO2 beam does, but close enough that you can see if things are working.

Also- on a 667II I worked on recently, the focus adjust/lens mount hardware came apart, and the focus lens dropped down and couldn't be adjusted.

Let us know what you find!
Jay

Jay Maechtlen