YAMAHA WAVERUNNER Water From Pisser

Pilot Water Outlet Nozzle

This is the terminal point of the cooling bypass line and represents the smallest diameter in the circuit. It is prone to clogging from sand, silt, or mineral deposits; even a tiny grain of sand can wedge in the orifice, creating a fluidic restriction that prevents the tell-tale stream from appearing even if the main cooling system is functioning.

Cooling System Bypass Hose

If the nozzle is clear, the internal bypass hose typically has an accumulation of debris at the Y-fitting or the stinger connection. Debris such as mud or salt-corrosion scale can settle in these low-pressure lines, obstructing the flow of water before it reaches the tell-tale exit.

Intake Grate/Impeller Wear Ring

The pilot stream relies on a specific amount of head pressure generated by the jet pump. If the impeller-to-wear-ring clearance is excessive or the intake grate is partially obstructed by seaweed or debris, the pump loses volumetric efficiency, and the lower-pressure bypass lines (the 'pisser') are the first to lose flow despite the engine potentially receiving enough water to avoid immediate overheat.

SKU: 63M-51312-01-94