Richard
The routine to level the deck should go like this...
1. Air the tires about 8-10 psi rear and 15-16 psi front.
2. Raise all four deck wheels to highest setting temporarily.
3. Set a height level to 2-1/2 inches (for leveling purposes)
4. On a flat surface and a block 2-1/2 inches depth, adjust right and left blade tips to just touch that block, and turn the turn-buckles to accomplish this setting. (be sure blades are not bent).
5. Check front to rear settings with your 2-1/2" block, and by adjusting the front bail, make the center blade front tip 1/4" lower than the rear tip of that blade.
6. Now drop the four deck wheels to where they are about 1/4" to 1/2 " clearance from your flat surface for whatever height setting you want to mow.
Should give you a very even and flat mown lawn now.