The wheel off the injector pump is the hand primer. It's a little plunger that is typically screwed down. You loosen the bleed screw on your filter housing. Lefty loosen the primer wheel and then move the plunger up and down until you've bled the air out. Tighten your bleed screw.
The other circled red thing on the right in your picture is the engine oil filler cap if I remember right.