Sierra 18-0333 Powerhead Base Gasket for Mercury/Mariner Outboard

The Sierra 18-0333 is a high-quality powerhead base gasket engineered specifically for Mercury and Mariner outboard motors. This critical gasket creates a reliable seal between the powerhead and engine base, preventing oil and water leaks while maintaining proper compression.

Key Features:

• Precision-engineered composite construction for superior sealing performance
• Designed to meet or exceed OEM specifications for exact fit and function
• Marine-grade materials resist fuel, oil, and saltwater exposure
• Direct replacement for Mercury Marine original equipment gaskets
• Ensures proper powerhead-to-base seal for optimal engine performance

Sierra Marine has earned the trust of boat builders and marine technicians for over 50 years by consistently delivering replacement parts that match OEM quality standards. Each gasket is manufactured to precise tolerances ensuring correct fitment the first time, making installation straightforward and reliable. This powerhead base gasket is an essential component during outboard motor rebuilds and routine maintenance to restore your engine to factory-fresh performance.