OK, you made me get mine out of the closet to look.....I used to run them in pattern.
Looking at the engine from the rear: Top left nipple goes to the innermost nipple on the carb. Bottom left nipple goes to the carb nipple closest to the needle valve. Top right nipple is "In" from the tank klunk line. Bottom right is a return line back to the tank.

Instruction say do not disassemble the pump, and "don't play with the pump screws"... Also, the tank is simply vented to the outside of the plane, not to muffler or pipe pressure.

It works well, and you can put your tank back on the CG if you wish.

Clair