Here are a couple of pictures describing the knife adjustment procedure.

On the side opposite the blades, you will find two holes in the upper corners of the Top Blade Carrier (CC4-2).
Inside are set screws that push out the top of the blade.

The normal factory adjustment puts a .03" - .06" gap between the carrier block and the back of the blade on the wide side, which I'm pointing at. The narrow side of the blade is allowed to touch the carrier block. The lighter the material to be cut, the less the gap can be. Heavier materials require more gap at the wide side. Increasing the gap on the wide side, brings the narrow side of the blade in, creating more blade pressure and blade wear. Purple or blue Loctite are used on the set screws and red Loctite is used on the two shoulder bolts that secure the top blade to the carrier.