jetski pump cone

The cone ends up right at the entrance of the nozzle. If this cone is longer, then it causes a smaller passage way for the water to flow into the nozzle, thus raising the velocity. However, if the cone is short and stubby, it will allow a larger volume of water to go through, thus giving you more bottom end acceleration for freestyle.

The Adjust-A-Thrust constantly shifts back and forth, changing the size of the pumps exit nozzle automatically. For maximum low end, the center shuttle is retracted, opening up the nozzle and allowing a large volume of water to be moved to accelerate the craft. As craft speed and pump pressure build, the tapered center shuttle is forced out into the exit nozzle, reducing its size and increasing water velocity, which increases top speed. Letting off the gas lets the shuttle backshift into low gear.