Sierra 18-4639 Marine Piston Kit for Outboard Engines

The Sierra 18-4639 Piston Kit is a precision-engineered replacement marine piston kit designed to meet or exceed original equipment specifications. Sierra marine engine parts are manufactured to deliver reliable performance in the demanding marine environment, making this kit a trusted choice for outboard engine rebuilds and overhauls.

Key Features:

• Meets or exceeds OEM specifications for a direct-fit replacement
• Complete piston kit — supplied with piston rings, wrist pin, and circlips as applicable
• Engineered for durability in high-horsepower, harsh marine conditions
• Manufactured by Sierra, a leading supplier of aftermarket marine engine components
• Interchangeable with select OEM parts — verify fitment using Sierra's parts finder or OEM cross-reference

Sierra International is a trusted supplier to OEM engine manufacturers and boat builders, and each Sierra product is held to strict quality standards. Always verify the part number and engine application before installation to ensure proper fit.