Sitting for an hour or more can cool the engine enough to need to allow for a cold start. They vary a lot with carburetion so you have to get used to your particular engine. If an engine starts best with choking or pumping the gas pedal then it is lean &/or cold. If it starts best by holding the gas clear to the floor then it is flooding. You just have to get familiar with it. If you have to use thwe choke a lot its possible the accel. pump in the carb is weak.
