Sierra Trigger Assembly 18-5797-1 for Mercury 50-70 HP 3 Cylinder Outboards

The Sierra Trigger Assembly, part number 18-5797-1, is an ignition trigger component engineered for Mercury outboard motors within the 50 to 70 HP range on 3 cylinder powerheads. The trigger assembly works within the ignition system to signal spark timing to the engine's electronic ignition components, and a worn or failing trigger can cause hard starting, misfiring, or a no-spark condition. This assembly is built to match the fit and function of the original Mercury trigger unit on the applicable engine serial number ranges, allowing for a direct in-place replacement without modification.

This part is cataloged under Mercury Outboard Stators & Triggers, the category Sierra uses for ignition trigger and stator replacement components. It is intended for technicians and boat owners replacing a failed or deteriorated trigger assembly as part of an ignition system repair or a preventive maintenance overhaul on the covered Mercury 3 cylinder outboards.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5797-1
• Product Type: Trigger Assembly
• Category: Mercury Outboard Stators & Triggers
• UPC: 808282392505
• Weight: 0.3 pounds
• Engine Fitment: Mercury 50 HP, 60 HP, and 70 HP, 3 cylinder outboards, within the applicable engine serial number ranges

Fitment

• Mercury 50 HP, 3 cylinder, serial numbers 6428681 to D000749
• Mercury 60 HP, 3 cylinder, serial numbers 6428681 to D000749
• Mercury 70 HP, 3 cylinder, serial numbers 4571652 to A996141

Frequently Asked Questions

What is the Sierra 18-5797-1 trigger assembly used for? It is an ignition trigger assembly for Mercury outboard motors, used to signal spark timing to the engine's ignition system on applicable 3 cylinder models.

Which Mercury outboards does the 18-5797-1 trigger assembly fit? It fits Mercury 50 HP and 60 HP 3 cylinder outboards with engine serial numbers 6428681 to D000749, and Mercury 70 HP 3 cylinder outboards with engine serial numbers 4571652 to A996141.

How much does the 18-5797-1 trigger assembly weigh? The Sierra trigger assembly, part number 18-5797-1, weighs 0.3 pounds.

Is the 18-5797-1 a direct replacement for the original Mercury trigger? Yes, the Sierra 18-5797-1 is built to match the fit and function of the original trigger assembly on the covered Mercury 3 cylinder outboards for direct installation.

What symptoms indicate a failing trigger assembly on a Mercury outboard? Hard starting, engine misfiring, or a complete loss of spark can indicate a worn or failing trigger assembly like the 18-5797-1 needs replacement.

Does the 18-5797-1 trigger assembly work on Mercury 80 HP outboards? No, based on the applicable fitment data the 18-5797-1 trigger assembly covers Mercury 50, 60, and 70 HP 3 cylinder outboards, not the 80 HP models.

How do I know if my Mercury outboard's engine serial number matches the 18-5797-1 fitment? Check your Mercury outboard's engine serial number against the ranges listed for this part: 6428681 to D000749 for 50 and 60 HP 3 cylinder models, or 4571652 to A996141 for 70 HP 3 cylinder models.

What category of part is the Sierra 18-5797-1? The 18-5797-1 is cataloged as a Mercury Outboard Stator & Trigger component, specifically a trigger assembly for the ignition system.

Can the 18-5797-1 trigger assembly be installed by a boat owner or does it require a mechanic? The 18-5797-1 is a bolt-in ignition component; installation typically involves accessing the powerhead's ignition system, which many experienced boat owners and marine technicians can perform.

Is the Sierra 18-5797-1 an OEM Mercury part or an aftermarket replacement? The 18-5797-1 is a Sierra-branded aftermarket trigger assembly manufactured to fit the applicable Mercury 3 cylinder outboard engines.