Of the generators that come with the KidWind Advanced Wind Experiment Kit, the smaller generator (less than 1 inch diameter, labeled “High Torque Generator”) is more suited to pumping water than the larger (1¼ inch diameter)generator is. The high-torque generator can be purchased separately.
High Torque Generator with Wires (KW-HIGEN, discontinued)
KidWind Advanced Wind Experiment Kit (KW-AWX)

The KidWind Small Water Pump with Tubing (KW-PUMP) requires 2-3 Volts and will draw 0.2-0.5 Amps to run. If your wind turbine is unable to create enough power, the pump will not run. To make sure the pump is functioning properly, try running it on a 9V battery to see if it spins. To maximize success, make use of the mechanical advantage that a gear box provides. Experimenting with your blade design will help you find the balance between torque and RPM necessary to deliver the proper voltage consistently without stalling the generator. Important variables include but are not limited to blade length, number of blades, and blade pitch (angle).

What are the specifications for the KidWind water pump?
What are the specs for the generator(s) in the KidWind kit?