Yamaha F50 Water Pump Impeller Replacement

Tools Needed

• Clamp or stand to secure the lower unit
• Screwdriver (if bolts are not already removed)
• Razor blade or scraper
• Scotch-Brite pad
• Silicone-based synthetic lubricant (e.g., Easy Slide)
• Grease

Safety

• Ensure the motor is not running dry; always connect it to a hose or place it in water.
• Be careful not to knock the key out of place during the procedure.

Steps

1. Secure the lower unit using a clamp or stand.
2. Inspect the water pump housing for any damage or salt buildup.
3. Remove the water pump impeller and inspect both sides for any wear or damage.
4. Scrape off any salt buildup or rough ridges using a razor blade or scraper.
5. Clean the impeller using a Scotch-Brite pad if necessary.
6. Lubricate the impeller with a silicone-based synthetic lubricant, ensuring not to use regular grease or engine oil.
7. Grease the threads of the bolts to seal out moisture and prevent corrosion.
8. Ensure the stainless steel insert is seated properly.
9. Apply a small amount of silicone grease to the o-ring seal at the bottom of the housing.
10. Align the impeller correctly, ensuring the key is in place and the notch for the keyway is visible.
11. Turn the drive shaft clockwise while holding the housing in place and push down on the housing to seat the impeller.
12. Snug the bolts evenly and give the shaft a little bit of a turn to ensure proper alignment.

Tips

• Inspect the impeller every year to ensure it is in good condition for the season.
• Overheating is the number one killer of outboard motors, so regular inspection of the water pump is crucial.
• Do not use anti-seize compounds with metal in them, as they can cause galvanic corrosion in a saltwater environment.