If the rubber plunger is good, making a seal, start with the pump shots rod in the closest hole for a maximum shot. Adjust the height of the top of the plunger correctly as to make sure the plunger is in the right spot of filling up the well and delivering a maximum amount of fuel into the carb.
You can try to work your way back on the attaching point of less shot if the closest hood is delivering to much.
Do you have extra/spare pump shot clusters?