Exhaust Manifold Gasket SIERRA 18-1204-1-9

Compatible Engines

Avoid exhaust leaks and power loss by choosing the original SIERRA exhaust manifold gasket. This critical component, part number 18-1204-1-9, is engineered for perfect fit and durability in harsh marine conditions. It is designed for popular MERCRUISER/OMC MCM engines with displacements of 120/2.5L and 140/3.0L, manufactured between 1983 and 1995. Precision molding prevents harmful gas leaks, ensuring stable engine operation and crew safety. Using the wrong gasket can damage the exhaust system, so investing in SIERRA quality protects your boat's longevity.

Installation and Maintenance Tips

Proper installation guarantees a leak-free system. Before removing the old gasket, ensure mating surfaces are clean, dry, and free of corrosion or old sealant residue. Note: never install a new gasket on a damaged manifold, as even minor scratches can cause leaks. Torque bolts to the manufacturer's specification in a crisscross pattern to ensure even pressure. Regular inspections prevent sudden failures during your trip.

• Exact Fit – guarantees system integrity and safety.
• High Durability – withstands high heat and saltwater exposure.
• Easy Installation – simplifies maintenance and minimizes downtime.
• Long-Lasting – SIERRA products are synonymous with quality.