Easiest way to cure a flooded engine is to remove the spark plug and with the choke off and with the plug hole pointing down flip the prop a couple times to clear the excess fuel from the cylinder. Maybe flipping the prop six times when choking to start the engine is too many and that is sending excess fuel to the engine. Try changing your starting routine by choke on, ignition on and throttle set at a high idle, then flip prop until the engine pops, then choke off and flip until it starts. It is somewhat unusual for the prop to want to bite you if the engine is timed correctly so maybe you should have the timing checked which should be at 28-30 deg BTDC.

Karol