Mercury – Exhaust Elbow | Dry Joint 4” / 7° Down Angle | Hot-Dipped, Powder-Coated Steel | 864309T02

Overview

There’s a certain comfort that comes from hearing your engine settle into a smooth, even rhythm as you ease away from the dock. When everything in the exhaust system is sealed and flowing the way it should, you feel it—not just as quiet operation, but as a kind of trust in your boat. The Mercury Marine Exhaust Elbow 864309T02 brings that feeling back. Built for the dry joint era of MerCruiser V6 and V8 engines, it’s the kind of part you install once and instantly appreciate every time you throttle up into open water.

Key Features

• Replacement exhaust elbow with a 4-inch (102 mm) outside diameter
• Features a 7-degree down-angle outlet for proper exhaust routing
• Hot-dipped and powder-coated exterior for strong corrosion resistance
• Designed for dry joint exhaust manifolds
• Durable cast construction engineered to handle heat, pressure, and vibration
• Built to Mercury Marine OEM specifications

Engine & Boat Compatibility

• Fits select MerCruiser V6 and V8 sterndrive engines manufactured by General Motors
• Compatible with engines using dry joint exhaust manifolds (model year 2002–2004)
• Works with engines including 305, 350, and 377 cubic inch displacement
• Suitable for cruisers, sport boats, runabouts, tow boats, and multi-purpose family vessels
• Designed for both sterndrive and inboard configurations

Performance & Practical Benefits

When an exhaust elbow is built right, you’ll notice the difference in the way your engine breathes. This Mercury elbow creates a tight, steady seal that keeps exhaust flowing smoothly while preventing unwanted water intrusion—one of the biggest threats to engine longevity. The dry joint design helps minimize corrosion points between the manifold and elbow, giving you a cleaner, more predictable exhaust system.

The 7-degree down-angle outlet keeps water flowing the way Mercury engineers intended, helping maintain a stable idle and a confident throttle response. The hot-dipped, powder-coated finish adds another layer of protection, standing up to years of heat cycles, salt spray, and engine bay moisture. Installation feels straightforward thanks to the precise OEM fit, and once it’s in place, the whole system feels tighter, quieter, and more secure.

Why Buy OEM

When you’re replacing a part that deals with heat, pressure, and water all at once, going with genuine Mercury Marine components isn’t just a preference—it’s smart boat ownership.

• OEM fit means no struggling to align bolt holes or force mismatched parts
• Designed specifically for dry joint exhaust systems from 2002–2004
• Built from materials chosen to resist internal and external corrosion
• Provides more reliable sealing than many aftermarket alternatives
• Helps avoid the cascading failures that can come from a poorly fitted exhaust component

If a friend at the marina asked whether to use aftermarket here, you’d probably shake your head and tell them to stick with OEM—because a part like this is too important to gamble on.

FAQ

Q1: Which engines does the Exhaust Elbow 864309T02 fit?

It fits 2002–2004 MerCruiser V6 and V8 engines with dry joint exhaust manifolds, including 305, 350, and 377 cubic inch models.

Q2: What makes this elbow different from aftermarket versions?

Its materials, angle, and internal passage dimensions match Mercury’s original engineering, ensuring proper flow and long-term reliability.

Q3: How do I confirm it’s the right one for my engine?

Check your engine serial number (0M600000–0W309999) and confirm that you have a dry joint exhaust manifold.

Q4: Can it be used in saltwater and freshwater?

Absolutely—the hot-dipped, powder-coated finish is designed for harsh marine environments.

Q5: Is installation straightforward?

Yes. Most boaters with basic mechanical experience find the OEM fitment clean and predictable.