I understand perfectly " prop flipping " however, that does not tell me at what point you engage the choke, turn on your ignition, throttle position.

Some guys have tried different variations of a starting procedure like closing the choke and flipping the prop at full throttle with the ignition off to prime.

Some guys rock the prop back and forth against compression with the ignition off to prime.

So without knowing your exact staring procedure I can't determine why your plug is getting overly wet. It could be an issue with the way you are trying to start the engine or it could be an issue with the carb. Without you explaining everything you are doing while trying to start the engine and in the order in which you are doing it, I can't be much help except to throw out a bunch of guesses.