This NGK spark plug CR6HS Stock #7023 is a great replacement for your inboard engine. It is compatible with Mercury part # 33-827859 and is perfect for ignition and starting systems. The spark plug is made with high-quality materials, ensuring durability and long-lasting performance. Whether you're a professional mechanic or a DIY enthusiast, this spark plug is easy to install and will provide reliable ignition for your boat. Don't let a faulty spark plug ruin your boating experience, upgrade to this NGK spark plug today.