Mercury – Exhaust Manifold | V6 Series | Corrosion-Protected Cast Iron | 99746A17

Overview.

There are a few parts on a MerCruiser engine that you simply expect to work without drama, and the exhaust manifold is one of them. When it’s right, your engine breathes easy, runs cooler, and feels smooth through every throttle setting. When it’s wrong, you feel it instantly — in the idle, in the temperature, and in your own peace of mind. That’s why boaters trust the 99746A17 Exhaust Manifold. It’s the kind of Mercury Marine part you install once and rely on every time you push away from the dock, no matter if you’re taking a slow cruise with family or opening up the throttle in deep water.

Key Features

• Designed as a direct-fit exhaust manifold for V6 MerCruiser engines
• Cast iron construction for long-term durability under high heat
• Corrosion-resistant coating on coolant passages and exterior surfaces
• Includes gasket, drain plug, o-ring, and drain elbow for a complete, ready-to-install setup
• Machined sealing surfaces ensure a tight, reliable fit on port or starboard side

Engine & Boat Compatibility

• Fits MerCruiser V6 engines, 220 and 262 cubic inches
• For model years 1985–2002
• Compatible with both sterndrive and inboard MerCruiser setups
• Common on sport boats, runabouts, family cruisers, fish-and-ski boats, and classic stern-drive hulls

Performance & Practical Benefits

A good manifold doesn’t call attention to itself — it simply keeps the engine breathing clean and running at the temperature it should. With the 99746A17, you’ll notice the difference in how steady the engine sounds and how smoothly the power comes on. The tight seal reduces exhaust leaks, keeping heat exactly where it belongs and protecting nearby components. Internal passages are coated to resist corrosion, so water flow stays consistent even after years of salt, heat, and vibration.

The included hardware makes installation easier and ensures you’re starting fresh with all new sealing points. Once installed, the manifold delivers that “tight and secure” feeling experienced boaters look for — the sense that every component is working together the way the factory intended. It’s a part designed not just for function, but for the confidence that lets you enjoy each moment on the water without worrying about what’s happening under the engine hatch.

Why Buy OEM

Seasoned boaters know that the exhaust system is not the place to gamble with aftermarket shortcuts. An OEM Mercury Marine manifold is engineered to match the exact flow characteristics and heat tolerances of the original system. That means no guessing on fitment, no mismatched ports, and no premature corrosion. It’s cost-effective in the long run because it lasts, installs correctly the first time, and protects the rest of your engine from the slow damage a poorly made manifold can cause. When you buy Mercury OEM, you’re choosing reliability born from real-world testing and years of engineering experience.

FAQ

Q1: Which engines does the 99746A17 manifold fit?

It fits MerCruiser V6 engines (220 and 262 cubic inch models) from 1985 through 2002, for both sterndrive and inboard setups.

Q2: What makes this manifold different from aftermarket options?

OEM construction, better casting quality, corrosion-resistant coating, and factory-matched fitment ensure long-term reliability and proper engine performance.

Q3: How do I verify this is the correct replacement?

Check your engine serial number and compare it with the fitment details in your owner’s or service manual.

Q4: Can this manifold be used in both freshwater and saltwater?

Yes — its corrosion-protected design supports both environments when maintained properly.

Q5: Is installation straightforward?

Most experienced boat owners or marine technicians will find the installation familiar, especially with the included gasket and hardware.