Mercury – Exhaust Elbow Gasket | Standard Cooling Series | Composite Marine Seal | 99777Q02

Overview

When you spend enough time on the water, you learn to appreciate the parts that quietly keep everything running right. The pieces you never think about until the day they fail—and the ones that earn your trust by never letting you down. That’s exactly how the 99777Q02 Exhaust Elbow Gasket feels: steady, dependable, and built for the kind of long days when the engine hum becomes its own kind of comfort. Whether you’re pushing out into open water or easing back toward the dock at sunset, knowing your exhaust system is sealed tight brings a sense of confidence no aftermarket substitute can match.

Key Features

• Creates a tight, reliable seal between exhaust elbow and manifold
• Marine-grade gasket material built to withstand heat, vibration, and pressure
• Designed specifically for standard cooling MerCruiser engines
• Precision-matched profile ensures factory-correct fitment
• Produced to Mercury Marine’s original engineering specifications

Engine & Boat Compatibility

• Fits MerCruiser 120 models (1983 and newer)
• Compatible with 140 and 3.0-liter inline engines
• Fits select V8 small-block MerCruiser engines built in 1982 and earlier
• Works with specific Ford Marine V8 engines equipped with standard cooling
• Common on runabouts, classic sterndrive cruisers, family bowriders, and fishing boats

Performance & Practical Benefits

A proper exhaust seal may not be flashy, but you’ll absolutely feel the difference when it’s doing its job. With the 99777Q02 installed, the joint between your exhaust elbow and manifold stays secure through every heat cycle, every wave, every long idle in the marina. The engine runs smoother. The exhaust note stays steady. And you avoid the subtle power loss and moisture issues that can creep in when a gasket starts to weaken.

This Mercury Marine part is engineered to resist the constant expansion and contraction that comes with marine use. It doesn’t crush unevenly or deteriorate quickly, and it handles vibration without losing its shape. That means better protection for the manifold, cleaner exhaust flow, and fewer surprises deep into the season. It’s a simple gasket, but in practice, it keeps your engine feeling tight, predictable, and ready for whatever kind of water day you have planned.

Why Buy OEM

For exhaust sealing, the difference between “fits” and “fits right” matters. A genuine Mercury Marine gasket is built from materials selected specifically for heat and pressure ranges found in standard-cooling MerCruiser engines. Aftermarket versions often cut corners—slightly different thickness, weaker materials, inconsistent compression—and that can lead to early leaks or repeated replacements. With the 99777Q02, you’re getting the exact part your engine was designed to use, backed by the reliability and long-term value that OEM parts are known for. It’s the kind of choice experienced boaters make because they’ve learned what works and what just causes headaches later.

FAQ

Q1: Which engines does the 99777Q02 Exhaust Elbow Gasket fit?

It fits select MerCruiser 120, 140, 3.0-liter, and specified Ford and General Motors V8 engines with standard cooling.

Q2: What sets this gasket apart from aftermarket versions?

It uses Mercury-approved materials and exact factory specifications, giving you consistent sealing and better long-term durability.

Q3: How do I confirm it’s the correct gasket for my engine?

Check your engine’s serial range and compare it to the compatibility notes in your owner’s or service manual.

Q4: Can it be used in both freshwater and saltwater?

Yes, it’s built for any marine environment when used on a compatible standard-cooling engine.

Q5: Is installation easy for most boat owners?

With the right tools and torque settings, installation is straightforward. Always follow your service manual for best results.