Accelerator Pump question for Wayne

[moneymanager]

I copied this from a Wayne Dempsey comment somewhere..."To check the adjustment of the accelerator pumps, place a small vial under the pump jet located inside the carburetor throat. You will have to fashion a small wire to hold the vial, as space is pretty tight inside the carburetor throat. Pump the throttle completely from closed to open twice, and measure the amount of fuel in the vial. For cold weather, the factory recommends 0.55-0.65 cc/ml of fuel. For warmer weather, it’s recommended to have 0.40-0.50 cc/ml of fuel. Adjust the length of the small linkage attached to the accelerator pump on the carb to increase or decrease this amount."

Wayne, I'm curious about the suggestion to pump the throttle twice. Others suggest once. But I find I get inconsistent readings doing this, even starting the motor between each check. Could you elaborate on your thinking here? Thanks,