Sierra 18-99419 Trigger Assembly, 3-Cylinder, Replaces Mercury 817029A9 - Fits Mercury 90/95 HP & Force 70/90 HP Outboards
Sierra 18-99419 Trigger Assembly, 3-Cylinder, Replaces Mercury 817029A9 - Fits Mercury 90/95 HP & Force 70/90 HP Outboards
The Sierra 18-99419 is a 3-cylinder trigger assembly for Mercury and Mariner outboard ignition systems. The trigger is the sensor component inside the ignition system that signals the CDI module when to fire each cylinder, so a worn or failed trigger typically causes misfiring, hard starting, rough idle, or a no-spark condition on one or more cylinders. Sierra 18-99419 is built as a direct fit replacement for the original Mercury/Mariner trigger on applicable 3-cylinder outboard powerheads, restoring correct ignition timing signal output across all three cylinders.
Construction uses an aluminum housing for the trigger body, and the unit is rated for 12 volt marine ignition systems. It ships as a single trigger assembly ready to install in place of the original equipment part. Because the trigger is matched to the engine's timing and cylinder count, always confirm cylinder count and horsepower rating against your outboard before ordering.
Specifications
- Brand: Sierra
- Manufacturer Part Number: 18-99419
- Cylinders: 3
- Material: Aluminum
- Voltage: 12 Volts
- Weight: 0.6 pounds
- UPC: 808282394509
- Category: Mercury Outboard Stators & Triggers
Fitment
- Mercury 90 and 95 HP, 1993-1997
- Force 70 and 90 HP, 1991-1995
Replaces (OEM)
- 817029A9
- 817029A3
Frequently Asked Questions
What does the Sierra 18-99419 trigger do? It is the ignition trigger sensor inside a Mercury/Mariner 3-cylinder outboard that signals the CDI module to fire each cylinder at the correct time, so replacing a worn Sierra 18-99419 restores proper ignition timing signal to all three cylinders.
Which engines does the Sierra 18-99419 fit? The Sierra 18-99419 fits 3-cylinder Mercury 90 and 95 HP outboards from 1993-1997 and Force 70 and 90 HP outboards from 1991-1995.
What OEM part numbers does Sierra 18-99419 replace? Sierra 18-99419 replaces Mercury OEM trigger numbers 817029A9 and 817029A3.
Is Sierra 18-99419 a direct OEM replacement? Yes, Sierra 18-99419 is designed as a direct fit replacement for the original Mercury/Mariner 817029A9 and 817029A3 trigger on applicable 3-cylinder outboards, with no modification required for installation.
How much does the Sierra 18-99419 trigger weigh? The Sierra 18-99419 trigger assembly weighs 0.6 pounds.
What material is the Sierra 18-99419 trigger made of? The trigger housing on the Sierra 18-99419 is aluminum.
What voltage ignition system is the Sierra 18-99419 designed for? Sierra 18-99419 is rated for 12 volt marine ignition systems, matching the standard electrical system on the Mercury and Force outboards it fits.
What symptoms indicate a trigger like the Sierra 18-99419 needs replacing? A failing trigger typically causes misfiring, hard starting, rough idle, or a loss of spark on one or more cylinders; if these symptoms appear on a 3-cylinder Mercury or Force outboard, the trigger is a common cause to check.
How many cylinders does the Sierra 18-99419 trigger cover? Sierra 18-99419 is built for 3-cylinder outboard powerheads.
Does the Sierra 18-99419 come as a complete assembly? Yes, it ships as a single complete trigger assembly ready to install in place of the original Mercury/Mariner unit.
Will Sierra 18-99419 work on a Force outboard, not just Mercury? Yes, in addition to Mercury 90 and 95 HP outboards, Sierra 18-99419 also fits Force 70 and 90 HP outboards from 1991-1995.