WHAT IT DOES
The pump impeller is made of flexible, rubber-like material that degrades over time. Changing it ensures water flow, but equally important, change it regularly ensures that the screws that hold the gear-case housing together do not corrode and lock tight.
RESULT OF NEGLECT
The most obvious and immediate effect is an overheating engine, which will at best end your boating day, and at worst burn up your engine.
COST TO PERFORM
It can cost $200 to $300 to have the water pump rebuilt by a professional. If you’re handy, you can do it in your driveway for $100 or less.
Even if the water pressure gauge indicates all is well on a three year – old pump, those screws might be welding the gear case together. If they do, you’ll replace the gear case for thousands, not hundreds, of dollars.