Ask around at the marina, and chances are that most boat owners have no idea when the water pump on their outboard was last serviced. Some people don’t even know that their engines have pumps.
The water pump is a very important part of any outboard. A pump that is blocked or working improperly will cause the engine to overheat, which can lead to permanent damage. If you suspect the outboard is running hot, it could be time to service the water pump. In most cases, this basically consists of replacing the water pump impeller. It’s not a complicated job, and the average do-it-yourselfer probably has the necessary tools. However, don’t try to do it with the boat in the water. Have it hauled if it’s large, or do the work when it’s on the trailer in the driveway. That way, you won’t lose anything vital.
The engine we serviced for this story was a 1996 115-hp Mercury. Outboards are very similar, and although the pictures might not look exactly like what you have, the sequence will be the same. I took the pictures as Adam Conte at Portside Marine in Danvers, Mass., serviced the pump. Working thoroughly and methodically, he completed the project in less than an hour, so a competent owner should be able to do the job from start to finish in less than two hours.
A step-by-step do-it-yourself guide
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