Sierra 18-3440 Water Pump Repair Kit for Yamaha Outboard - 25-40HP

The Sierra 18-3440 is a comprehensive water pump repair kit designed for Yamaha outboard motors ranging from 25 to 40 horsepower. This complete service kit provides all the essential components needed to restore your outboard's cooling system to proper operating condition without having to purchase individual parts or a complete pump housing assembly.

Kit Includes:

• Neoprene impeller for reliable water pumping performance
• Wear plate to protect pump housing
• Insert cup (cartridge)
• Water pump gaskets for proper sealing
• Installation bolts with washers
• Woodruff key for impeller shaft
• Water seal and O-rings
• Pump cover

Applications:

• Yamaha 25HP (T25 series, 2001-2019, 2-stroke and 4-stroke)
• Yamaha 30HP (F30 series, 2001-2019, 4-stroke)
• Yamaha 40HP (F40 series, 2000-2019, 4-stroke)

This repair kit replaces Yamaha OEM part number 66T-W0078-00-00 and cross-references with Mallory 9-48610. The kit does not include the pump housing. Sierra water pump components are manufactured from high-quality neoprene rubber and metal alloys designed to meet or exceed OEM specifications for durability in harsh marine environments. Regular water pump maintenance is essential for proper engine cooling and longevity—experts recommend inspecting the impeller annually and replacing it every two to three seasons to ensure optimal performance.