Sierra 18-3012 Marine Neoprene Impeller with 6 Fins for Mercury/Mariner Outboard

The Sierra 18-3012 is a high-quality marine water pump impeller designed specifically for Mercury and Mariner outboard motors ranging from 3.5 HP to 9.8 HP. This critical cooling system component features durable neoprene construction with six flexible vanes molded around a brass hub, engineered to meet or exceed original equipment specifications.

Key Features:

• 6-fin neoprene impeller construction for reliable performance
• Brass hub for corrosion resistance and durability
• Direct replacement for Mercury Marine part number 47-22748
• Cross-compatible with Mallory 9-45308, GLM 89600, and Johnson Evinrude OMC 508388, 775465
• Meets or exceeds OEM specifications for quality assurance
• ISO 9001 certified manufacturing facility

Water pump impellers are essential for maintaining proper engine cooling in marine applications. The flexible vanes rotate on an eccentric within the pump housing, drawing water through the cooling system. Marine professionals recommend replacing impellers annually or every 100 hours of operation to prevent engine overheating and costly damage. Always keep a spare impeller on board for emergency replacements during extended boating trips.