Is pumping the throttle the best was to get gas back in the lines?
No, pump the throttle just pumps what is in the carb. If nothing is in the carb, there is nothing to pump
If you have mechanical fuel pumps, crank 10 seconds, let sit for 30 seconds and repeat. Do that twice then try a couple pumps and crank
Can also drip just a very slight bit of gas down the carb. Note very little, table spoon. Then crank, it should fire and run for a short time. Can repeat if gas has not made it to the carb yet