Plate Marker Issues

I have a 4800 table. It came with the plate marker and I just finished installing plate marker. Everything seemed fine until it was time to get the plate marker centered in the plasma hole. The plate marker does not extend to the plate. It stops about 1/2 in from the plate. Plenty of air pressure. It operates and retracts perfectly but if it's not close to the metal. Where is the adjustment?

I'm sure it's me!