About Water Pumps

The water pump in an outboard is made to last quite a while under normal operating conditions, but does eventually wear out.  That being said, a water pump can be destroyed in a couple of seconds if run out of water.

YAMAHA, for example, recommends the inspection of the water pump once a year or 100 hours, replacing it if needed.  They recommend the replacement of the water pump every 3 years.

When I talk to my customers, I try to find out when they last replaced their water pump.  If they are unsure, I recommend replacing it so they can get back on schedule.  If it has been more than 4 years, I strongly recommend replacing it. 

It is also important to replace the water pump to make sure that all of the bolts come out, and the driveshaft splines & bushing get greased up.

Its not unusual for a motor to come in for repair that is 10-15 years old and has never had the pump replaced.  Sometimes, it will come apart just fine, but other times, it is seized up so bad that the motor is basically no good because it cannot come apart.  This is an especially common problem for smaller motors.