CDI Electronics 18-99452 134-9021-2 Mercury Mariner 2-Cylinder Ignition Trigger

The CDI Electronics 134-9021-2 is a direct-replacement ignition trigger for Mercury and Mariner 2-cylinder outboard engines. Also sold under Sierra part number 18-99452, this trigger timer base is designed specifically for 1995–1999 30 HP and 40 HP engines equipped with TPM (Throttle Position Module) ignition systems.

The trigger is a critical component of the outboard's Capacitor Discharge Ignition (CDI) system. It monitors flywheel magnet position and transmits a low-voltage timing signal to the switch box (power pack), telling it precisely when to release voltage to the ignition coils and fire the spark plugs. A worn or failed trigger commonly causes no-start conditions, misfires, or erratic ignition timing.

Key Features:

• Direct OEM replacement for Mercury and Mariner 2-cylinder outboards
• Designed for 1995–1999 30 & 40 HP engines with TPM ignition modules
• Replaces OEM part numbers: 99021A11 and 99021A14
• Also cross-references CDI part number 134-9021-2 and Sierra 18-99452
• Manufactured by CDI Electronics, a leading name in marine ignition components
• Sold as a single unit

CDI Electronics is the industry standard for marine ignition replacement parts, offering precision-engineered components that meet or exceed original equipment specifications. This trigger is backed by CDI's reputation for reliability in demanding marine environments.