Sierra 18-4224 Drain Elbow Assembly, Replaces Mercruiser 22-806926A1, 3/4 Inch NPT

The Sierra 18-4224 Drain Elbow Assembly is a stainless steel replacement fitting used in the cooling system of MerCruiser I/O sterndrive engines. It threads into the exhaust manifold or manifold gasket location using a 3/4 inch NPT thread and provides the drain connection point for the raw water cooling circuit, allowing water to be routed away from the manifold during operation or drained from the block during winterization and service.

Built from stainless steel with a machined finish, the elbow is designed to resist the corrosion and heat exposure typical of the exhaust manifold area on gasoline sterndrive engines. It is finished in gray and supplied as a single-piece assembly, making it a straightforward drop-in replacement when an original elbow has corroded, cracked, or seized.

This elbow is applicable to MerCruiser I/O cooling systems and is built to meet or exceed the performance of the original equipment part it replaces, giving boat owners and marine technicians a reliable way to restore the manifold drain connection without sourcing a used or hard-to-find factory part.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-4224
• Product Name: Drain Elbow Assembly
• Thread Size: 3/4 inch NPT
• Material: Stainless Steel
• Color/Finish: Gray, machined
• Item Dimensions: 7.25 x 5.63 x 2.13 inches
• Weight: 0.07 pounds
• Number of Pieces: 1
• Application: I/O - MerCruiser cooling system
• UPC: 808282125141
• OEM Cross-Reference: 22-806926A1, 22-862210A01

Fitment

Designed for MerCruiser I/O sterndrive engines in the cooling system application, including MCM/MIE V-6 and V-8 engines with center rise exhaust manifolds.

Replaces (OEM)

• 22-806926A1
• 22-862210A01

Frequently Asked Questions

What does the Sierra 18-4224 Drain Elbow Assembly replace? It is a direct replacement for MerCruiser exhaust manifold drain elbows 22-806926A1 and 22-862210A01, so any boat currently fitted with one of those OEM elbows can use the Sierra 18-4224 instead.

What thread size does this drain elbow use? The Sierra 18-4224 uses a 3/4 inch NPT thread, matching the original MerCruiser manifold drain connection.

What engines is the 18-4224 drain elbow designed for? This drain elbow fits MerCruiser I/O sterndrive engines in the cooling system, including MCM/MIE V-6 and V-8 engines with center rise exhaust manifolds.

What material is the Sierra 18-4224 made from? It is machined from stainless steel with a gray finish, giving it resistance to the heat and corrosion found at the exhaust manifold drain location.

How much does the 18-4224 drain elbow weigh? The Sierra 18-4224 Drain Elbow Assembly weighs 0.07 pounds.

What are the dimensions of this drain elbow? The Sierra 18-4224 measures 7.25 x 5.63 x 2.13 inches.

Is the Sierra 18-4224 a genuine Sierra part or aftermarket? It is a Sierra-branded replacement part manufactured to meet or exceed the performance of the original MerCruiser equipment it replaces, rather than a factory MerCruiser part.

How many pieces come in the 18-4224 assembly? The Sierra 18-4224 ships as a single-piece drain elbow assembly.

Where does the 18-4224 drain elbow install on the engine? It threads into the exhaust manifold drain location using its 3/4 inch NPT fitting, forming part of the raw water cooling circuit on MerCruiser I/O engines.

Why would I need to replace a drain elbow like the 18-4224? Drain elbows in the manifold cooling circuit are prone to corrosion over time; the Sierra 18-4224 provides a stainless steel replacement when the original elbow has corroded, cracked, or seized.