There is nothing wrong with pumping the throttle to help prime the engine. In fact on a cold day the engine will sometimes start to die right after it starts. A few quick pumps will give the engine the extra fuel it needs to keep running.
Similarly a slightly under primed engine will start with a few pumps on the throttle. The only precaution is to only pump the throttle while the engine is being rotated by the starter or all ready turning on its own.