Unleash the Power: How to Fix a Broken Water Pump on Your Yamaha 250 Outboard

Maintaining your Yamaha 250 outboard is crucial for ensuring optimal performance and longevity. Replacing the water pump is a critical component of regular maintenance, and this comprehensive guide will provide you with step-by-step instructions on how to change the water pump on your Yamaha 250 outboard.

Tools and Materials You’ll Need

Before getting started, gather the following tools and materials:

• New Yamaha 250 outboard water pump kit
• 10mm socket wrench
• 12mm socket wrench
• Flathead screwdriver
• Phillips screwdriver
• Torque wrench
• Rags
• Gasket sealant

Safety Precautions

• Disconnect the battery before starting any work.
• Allow the engine to cool down completely before beginning.
• Wear appropriate safety gear, including gloves and eye protection.
• Work in a well-ventilated area.

Step-by-Step Instructions

1. Remove the Lower Unit

• Place the outboard in neutral.
• Remove the drain plug and drain the gear oil.
• Using a 10mm socket wrench, remove the bolts securing the lower unit to the midsection.
• Carefully separate the lower unit from the midsection.

2. Remove the Water Pump Housing

• Using a 12mm socket wrench, remove the bolts securing the water pump housing to the lower unit.
• Gently pry the water pump housing away from the lower unit.

3. Inspect the Water Pump Impeller

• Inspect the water pump impeller for any damage or wear.
• Replace the impeller if necessary.

4. Remove the Shaft Seal

• Using a flathead screwdriver, carefully remove the shaft seal from the lower unit.

5. Install the New Shaft Seal

• Apply a thin layer of gasket sealant to the new shaft seal.
• Press the new shaft seal into the lower unit.

6. Install the Water Pump Housing

• Apply a thin layer of gasket sealant to the gasket surface of the water pump housing.
• Carefully align the water pump housing with the lower unit and secure it using the bolts.

7. Install the Lower Unit

• Lift the lower unit into position and align it with the midsection.
• Secure the lower unit using the bolts.

8. Fill the Gear Oil

• Replace the drain plug and fill the lower unit with the appropriate amount of gear oil.

9. Connect the Battery

• Reconnect the battery.

Troubleshooting Tips

• If you experience water leaking from the water pump housing, check the shaft seal for proper installation.
• If the water pump is not pumping water, ensure that the impeller is properly installed and that there are no obstructions in the water intake.
• If you have difficulty removing the water pump housing, use a penetrating oil to loosen the bolts.

Wrapping Up

Changing the water pump on a Yamaha 250 outboard is a straightforward task that can be completed in under an hour with the right tools and materials. By following these step-by-step instructions, you can ensure that your outboard is properly maintained and operating at its peak performance.

Frequently Asked Questions

Q: How often should I change the water pump on my Yamaha 250 outboard?
A: Yamaha recommends changing the water pump every 100 hours of operation or annually, whichever comes first.

Q: What are the signs of a failing water pump?
A: Signs of a failing water pump include overheating, reduced water pressure, and engine noise.

Q: Can I change the water pump myself?
A: Yes, with the proper tools and materials, you can change the water pump on your Yamaha 250 outboard yourself. However, if you are not comfortable working on your outboard, it is recommended to have it serviced by a qualified mechanic.