Best Fuel Pump Advice for Newb...

If the vehicle has been sitting a while, the carb and lines may empty, but it is not nec to continue cranking for several seconds.
After 2 crankshaft revolutions the cams one revolution has cycled the pump's lever once, compressing a spring/diaphram inside the pump.
Stop cranking, wait a sec. and the spring/diaphram maintains suction for a coupla seconds moving fuel. Give it another short crank,wait a sec. the lever once again cycles the pump, fuel moves after key released.
I usually gently pump throttle on 3 rd try, and it usually fires pretty quick.
Helps when you have a weak battery to understand pump function.
Cheers
True on all manual diaphram pump vehicles to my knowledge.