Sierra 18-4134 Marine Piston Kit .030 Oversize Bore for Mercury Outboard Engines

The Sierra 18-4134 is a .030 oversize (O.S.) piston kit engineered as a precision replacement for Mercury and Mariner outboard engines. Designed for use during engine rebuilds where the cylinder bore has been bored out to .030 over standard size, this kit restores proper compression and engine performance to OEM standards.

Key Features:

• .030 Oversize bore — engineered for engines that have been bored .030" over standard
• Supplied complete with piston rings, wrist pin, and circlips — everything needed for installation
• Manufactured to meet or exceed OEM specifications for fit, form, and function
• Built to withstand the high horsepower demands and harsh marine environments of outboard use
• Backed by Sierra's comprehensive manufacturer's warranty
• Part of Sierra's extensive marine engine parts lineup — a trusted name in aftermarket marine replacement parts

Sierra Marine is a leading supplier of marine engine and drive components, supplying parts to OEM engine manufacturers and boat builders for over 35 years. The 18-4134 piston kit delivers the reliability and durability needed for a lasting engine rebuild on Mercury and Mariner outboard applications.