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.
The exact location of an impeller or a water pump repair kit on Boats.net 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.
How to Find Water Pump Repair Kits & Impellers
Step 1. Select your outboard’s make and model from the Shop By Brand dropdown menu on the Boats.net homepage, followed by your outboard’s make and model by HP or by year.
Step 2. Locate your outboard model’s respective parts diagram for water pump repair kits. For Yamaha outboards, it’s Repair Kit 2.
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 Outboard Parts 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.
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. The individual impeller for the Yamaha 225 in the video is also found in the Lower Casing Drive 3 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.
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.