Sierra 18-99309 Ignition Condenser for Mercury Mariner Outboard Engines

The Sierra 18-99309 is a replacement ignition condenser designed for Mercury and Mariner outboard engines equipped with the red module ignition system. This essential ignition component ensures reliable spark delivery and proper engine timing for smooth operation.

Key Features:

• Designed for Mercury/Mariner 4 HP, 4.5 HP, 7.5 HP, 9.8 HP, and 20 HP outboard engines
• Compatible with red module ignition systems on 1972-1989 models
• Replaces Mercury OEM part numbers 336-4463 and CDI 994-4463
• Marine-grade construction built to withstand harsh saltwater environments
• Meets or exceeds original equipment specifications

This condenser is a critical component of the breaker point ignition system, storing and releasing electrical energy to create a strong spark at the spark plug. Regular replacement during tune-ups helps maintain optimal engine performance and prevents misfires.