WATER TUBE 68D-G4360-00 PAF4-02040001S

Function and technical context

This water tube is part of the engine cooling circuit, conducting the coolant from the engine block to the heat exchange systems. In Yamaha outboard and sterndrive engines, water tubes are vital elements that transport coolant under pressure, allowing efficient dissipation of heat generated during combustion. A cracked, clogged or deteriorated tube compromises coolant circulation, causing engine overheating, reduced power and risk of catastrophic breakdown while navigating.

When to replace this part?

The water tubes require routine inspection at every seasonal inspection, especially if the engine has been exposed to extreme temperatures, salt water, or prolonged inactivity. Typical symptoms include visible coolant leaks, limescale deposits on connections, hardening or brittleness of the material after years of use, or abnormal readings on the engine temperature sensor. Preventive replacement during regular maintenance prevents unexpected blockages and costly breakdowns when the boat is on the water.

Equivalent manufacturer part numbers