Sierra 18-99218 Switch Box for 2-Cylinder Mercury Outboard Engines

The Sierra 18-99218 is a high-performance aftermarket switch box (also called a power pack or CDI module) designed for 2-cylinder Mercury and Mariner outboard engines. This critical ignition component controls the timing and firing of the ignition coils, ensuring reliable engine starts and smooth operation.

Key Features:

• Direct replacement for Mercury OEM part numbers 339-6222A1, 339-6222A4, 339-6222A8, and 339-6222A10
• Replaces CDI part number 114-6222 for convenient cross-compatibility
• Compatible with various 2-cylinder Mercury outboard models including 4HP Model 40 (1976-1980), 7.5HP Model 75 (1974-1986), 9.8HP Model 110 (1974-1985), and 20HP (1974-1981)
• Requires Orange, Red, or Green ignition coils (not compatible with Black or Blue coils)
• Manufactured to meet or exceed OEM specifications for reliable performance
• Engineered to withstand the harsh marine environment

This switch box is designed for professional installation by a qualified marine mechanic. Sierra is a trusted name in marine aftermarket parts, providing quality replacement components backed by their industry-leading customer satisfaction warranty.