Some suggestions on your first startup Raphael when you get your engine.
Use the factory settings; the carb needle should be around 1 turn open. After it warms up you can close it a bit to around 7/8th turn closed.
Use a pulley and rope starter if you have one. I actually have never been able to start my engine by hand flipping the flywheels.
Preheat the engine cylinder head with a hair dryer and hot water in the hopper.
Good luck and let us know how it goes. This is a different little beast!