Mercury – Cylinder Head Gasket | Yamaha 4.2L Series | Marine-Grade Composite | 8M6010321

Overview

There’s a certain confidence that settles in when your engine fires up clean and strong—the kind of confidence you only get when every critical seal in your motor is doing its job. On a big 4.2-liter Yamaha outboard, nothing is more important than keeping combustion where it belongs. That’s why boaters who run hard and expect reliability turn to a gasket they can trust. The Quicksilver 8M6010321 Cylinder Head Gasket delivers that steady, reassuring performance, giving you the peace of mind that your engine is sealed tight whether you’re cruising at sunrise or making a long offshore run home at dusk.

Key Features

• Designed for select 4.2-liter Yamaha outboards
• Meets all original equipment specifications for sealing pressure and durability
• Fits either the port or starboard cylinder bank
• Marine-grade composite construction engineered for heat, pressure, and water intrusion
• Cylinder head gasket only; installation hardware sold separately
• Replaces Yamaha OEM part number 6CB-11181-00-00

Engine & Boat Compatibility

• Built for Yamaha 4.2L four-stroke outboards
• Commonly found on offshore center consoles, bay boats, dual consoles, and coastal fishing rigs
• Suitable for high-load applications, long-distance cruising, and heavy daily use
• Works with both freshwater and saltwater configurations when installed per manufacturer guidelines

Performance & Practical Benefits

A cylinder head gasket may not be the flashiest component on your outboard, but you feel its importance in every smooth throttle push and steady idle. The Quicksilver 8M6010321 is engineered to hold firm against constant heat cycles, high compression, and the pounding vibration marine engines face mile after mile.

Once installed, you’ll notice how confidently your engine settles into gear—no hesitation, no wandering idle, just a tight, secure seal that supports clean combustion and proper cooling. It’s the kind of part that just quietly does its job, letting you focus on the ride instead of worrying about what’s happening under the cowling.

Because it fits either side of the powerhead, you won’t have to double-check left-versus-right differences during ordering. And with OEM-level specifications, it installs with the right fit and crush profile on the first try, preventing the leaks or uneven seating that can happen with lower-grade aftermarket options.

Why Buy OEM

Choosing a genuine Quicksilver gasket isn’t about buying the most expensive option—it’s about avoiding the problems that come from lesser ones. An OEM-spec gasket gives you:

• A perfect match to Yamaha’s original sealing surface
• Long-term reliability under extreme heat and pressure
• Protection against coolant seepage and compression loss
• Consistent thickness and uniformity for proper torque loading

If you want your outboard to keep running strong season after season, this is the kind of part you don’t compromise on.

FAQ

Q1: Which Mercury engines does this fit?

This part does not fit Mercury engines. It’s a Quicksilver replacement designed for select Yamaha 4.2L outboards.

Q2: What makes this different from aftermarket gaskets?

It’s built to precise OEM specifications, ensuring proper sealing, correct crush, and long-term reliability.

Q3: How do I confirm it fits my Yamaha?

Check your engine model and serial number, then verify with your service manual.

Q4: Can it be used in saltwater?

Yes. With proper maintenance, it performs reliably in both saltwater and freshwater environments.

Q5: Is installation straightforward?

Most skilled DIY boaters can handle the install, but a torque wrench and full adherence to Yamaha procedures are essential.