Mercury – Brass Drain Plug | Cooling System Component | Machined Brass | 16951T1

Overview

Draining your engine’s cooling system should be simple, secure, and worry-free. The Mercury Marine 16951T1 Brass Drain Plug makes that possible. Built from solid machined brass, this plug threads cleanly into most MerCruiser engine blocks and exhaust manifolds, allowing you to easily drain water for winterizing or antifreeze changes. Designed to handle marine environments without seizing or corroding, it’s a small piece of hardware that delivers long-term reliability and peace of mind every season.

Key Features

• Purpose: Allows quick and clean draining of water or coolant from the engine block or exhaust manifold.
• Material: Made from machined brass for corrosion resistance and lasting strength.
• Fitment: Standard ¼-inch NPT thread fits most MerCruiser engine blocks and manifolds.
• Design: Precision-machined for a tight seal and easy removal.
• Compatibility: Works with both closed cooling and raw water systems.
• Ease of Use: Installs and removes easily using standard hand tools.

Engine & Boat Compatibility

• Fits most MerCruiser sterndrives and inboard engines.
• Compatible with engine blocks and exhaust manifolds designed for ¼-inch NPT plugs.
• Works with raw water-cooled and closed cooling system configurations.
• May also fit other brands of inboard or sterndrive engines using standard-thread fittings.
• Common on cruisers, runabouts, and tow boats with GM-based MerCruiser powerplants.

Performance & Practical Benefits

The 16951T1 drain plug makes maintenance easier and more reliable. It provides a tight, leak-free seal while resisting rust, galling, or thread damage. When it’s time to drain or winterize, the brass construction ensures the plug backs out smoothly, even after long exposure to water and heat.

Replacing old or worn plugs with this OEM version helps prevent seized fittings and reduces the risk of freeze damage in cold weather. Once installed, it stays snug and dependable — one less thing to worry about during seasonal maintenance.

Why Buy OEM

Not all brass plugs are created equal. Some aftermarket parts use lower-grade material or imprecise threads that don’t seal properly. The Mercury 16951T1 is a genuine OEM part, made to exact Mercury standards. It fits perfectly, resists corrosion, and provides the strength and reliability marine engines demand.

Mercury engineers designed it for years of trouble-free use in both fresh and saltwater conditions. It’s a small but vital component that ensures your cooling system stays safe and serviceable season after season.

FAQ

Q1: Which engines does this plug fit?
It fits most MerCruiser sterndrive and inboard engines with ¼-inch NPT block or manifold fittings.

Q2: Can it be used for both raw and closed cooling systems?
Yes. It’s designed for use with both types of systems.

Q3: What’s it made of?
It’s made from solid machined brass, chosen for strength and corrosion resistance.

Q4: How do I install it?
Thread it into the drain port using a wrench — no special tools are needed.

Q5: Can I use it in saltwater environments?
Absolutely. The brass finish prevents corrosion and pitting, even after long-term salt exposure.