Anothe tip Kevin
You state "FULL throttle" when flipping with the choke on. Instead try - Switch OFF, full throttle, choke on, turn over or flip engine til fuel starts to run out of carb - THEN - fast idle, Switch ON, choke on, flip til it sputters, take off choke, set throttle at idle or a little above, flip to start. Never flip with the switch ON and throttle at full.