CDI Electronics 18-99408 Mercury Trigger 4 Cylinder Ignition

The CDI Electronics 18-99408 (CDI part number 134-9021-4) is a precision-engineered trigger assembly designed for Mercury and Mariner 4-cylinder outboard engines. This critical ignition component relays crankshaft position to the ignition system, ensuring each spark plug fires at the precise moment for optimal engine performance.

Key Features:

• Direct replacement for Mercury/Mariner 4-cylinder engines from 1988-1997
• Fits 80 JET, 100, 115, and 125 HP outboard models
• Replaces OEM part numbers: 99021A2, 99021A6, 99021K2, 475095, 615095, 616095, F615095, 300-475095, 300-F616095, 300-888792
• Marine-grade construction resists heat, vibration, and moisture intrusion
• Plug-and-play installation matches OEM wiring connectors
• Provides accurate spark timing for improved throttle response and fuel efficiency

This trigger assembly is essential for maintaining reliable ignition performance in your Mercury outboard. CDI Electronics manufactures this component to meet or exceed OEM specifications, providing a dependable replacement at a competitive price point. Compatible with both recreational and commercial marine applications.