Yamaha 4-Stroke Outboard Water Pump Repair Kits

A boat's water pump is a belt-driven pump that derives its power from the crankshaft of the outboard.

Designed as a centrifuge, the water pump draws cooled fluid from the radiator in through the pump's center inlet. It then circulates the fluid outward into the engine and back into the car's cooling system. As a general rule of thumb, the water pump impeller should be replaced every other season. A water pump repair kit is available for almost all outboard models. As a general rule of thumb, the water pump impeller should be replaced every other season. A water pump repair kit is available for almost all outboard models. Most marine engines will have a raw water pump with a flexible impeller. It is used to pump raw water from outside the boat through the engine's raw water cooling plumbing. These impellers are very reliable but some care is required. Outboard water pumps are simple designs. The pump draws water through the intakes and up into the housing. The impeller blades (vanes) touch the liner at lower speeds as the driveshaft turns, but as the engine revs up, the impeller blades bend back away from the housing liner. Replace and repair your Yamaha outboard with a purchase from the PartsVu catalog of Yamaha Outboard Thermostats, Water Pump Repair & Cooling Components today.

The engine water pump is a crucial component of any outboard, but most people can't remember the last time they had their water pump serviced or even replaced. And if that's the case, it's probably time to replace it. They should never be run dry. It only takes a very short time for them to disintegrate running dry. Typically when they're replaced or the pump housing is opened for inspection, they should be lubricated to give them a chance to suck in the water initially without abrading against the sides of the pump. Once water starts flowing through, this will lubricate them. Some manufacturers claim that oil based grease is bad for the rubber or other material of which the impeller is made and suggest using something like a dishwashing soap or other proprietary lubricant. Others say that oil based grease is fine. Many mechanics use oil based light grease because it doesn't last long after water is introduced to the inside of the pump body.