Description:

Fits: Yamaha YZ125 2005-2019. By casting a totally new water pump cover, Boyesen was able to maximize the flow through the unit. Boyesens design takes advantage of everything from Bernoullis Effect to biological studies. Unlike the stocker, Boyesens water inlet has an increasing diameter and artfully curved shape. This is a vast improvement over most stock inlets, which decrease in diameter as they near the impeller and have a 90-degree bend at the pump. Patented nautilus style impeller for hydrodynamic efficiency, reducing heat, gaining horsepower and extending engine life. Can reduce engine temperatures by as much as ten degrees.