How to Find a Water Pump Impeller Replacement

An impeller that doesn’t work correctly causes an outboard engine to overheat, leading to severe powerhead damage. An outboard engine’s water pump impeller needs to be serviced after every 100 hours of use or once per year. 

Make replacing the impeller part of your outboard’s yearly maintenance schedule. The impeller can be bought individually or as part of a water pump repair kit. 

Yamaha outboard impeller

The exact location of an impeller or a water pump repair kit on varies among manufacturers. OEM outboard water pump parts can usually be found in the lower casing or lower unit diagram on the page for your model. This guide shows how to find an OEM replacement water pump repair kit for a Yamaha outboard, but the process is similar for other makes and models. 

Buy outboard water pump repair kits

Buy outboard water pump impellers

NOTE: We used a 2005 Yamaha LF225TXR outboard as an example in the video above.

How to Find Water Pump Repair Kits & Impellers

Step 1. Select your outboard’s make and model from the Shop OEM Parts dropdown menu on the homepage, followed by your outboard’s make and model. 

How to find water pump impeller

How to find outboard water pump impeller by horsepower

How to find outboard water pump impeller by model

Step 2. Locate your outboard model’s respective parts diagram for water pump repair kits. For Yamaha outboards, it’s Repair Kit 2. 

How to find outboard water pump impeller by component

NOTE: We used a 2005 Yamaha LF225TXR as an example in the video, and its water pump repair kit parts diagram is found in Repair Kit 2.  For other outboard makes and models, the menu item may read “Water Pump Impeller Kit” or something similar. 

Step 3. Find the Water Pump Repair Kit on the list next to the parts diagram for your outboard.

Yamaha F225 outboard water pump repair kit

NOTE: For the Yamaha LF225TXR in the video, it’s #26 on the parts diagram, but it could be different for your outboard’s make and model. Some parts can also be found in other parts diagrams for a particular outboard’s make and model. For example, the individual impeller for the Yamaha 225 in the video is also found in the Lower Casing Drive 3 parts diagram.

Yamaha outboard water pump impeller parts diagram

Inspecting the Water Pump Impeller

Remove the outboard’s lower unit (gearcase) and check the impeller for gouges, cracks and other wear. The rubber should also be flexible, not stiff.  

How to find water pump impeller

Yamaha outboard water pump impeller

Lack of use can cause an impeller to get dry and brittle. If the motor’s been sitting unused for a while or you bought a used outboard, replace the impeller immediately. Impellers are inexpensive to replace and more than worth the little time and money it takes to change them out

Need a little help swapping out the impeller or fixing the water pump on your outboard engine? Watch the video above to see how to replace the water pump on a Yamaha F225 outboard



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