Sierra Trigger Assembly 18-5798-1, OEM Equivalent Mercury Marine 96455A9, Fits 105 JET, 115 6 Cyl, V135 Outboards

The Sierra Trigger Assembly, part number 18-5798-1, is an ignition trigger component designed for outboard engine mount installation on select Mercury outboard powerheads. The trigger assembly works with the engine's ignition system to signal spark timing, and this unit is built for gasoline-fueled, freshwater-use outboard applications. It is constructed of durable aluminum for reliable performance in the marine engine environment.

This trigger assembly is compatible with 6 cylinder outboard engines and is rated up to 225 horsepower. It is designed as a mount-type trigger that installs directly onto the engine, and it serves as a Mercury Marine equivalent replacement part, cross-referencing to Mercury Marine part number 96455A9. Coverage spans several Mercury outboard engine families and serial number ranges, including the 105 JET, 115 6 cylinder, and V135 models, making it a straightforward replacement option when the original trigger assembly on these engines needs service.

Each unit ships as a single trigger assembly, ready to install in place of a worn or failed factory trigger. Because outboard trigger assemblies are matched to specific engine serial number ranges, confirm your engine's serial number falls within the applicable range before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5798-1
• Product Type: Trigger Assembly
• Weight: 0.37 pounds
• Material: Aluminum
• Color: White
• Mounting Type: Engine mount trigger assembly
• Engine Type: Marine, outboard
• Engine Compatibility: 6 cylinder outboard engines
• Fuel Type: Gasoline
• Maximum Horsepower: 225 horsepower
• Recommended Use: Fresh water
• Unit Count: 1 trigger assembly

Fitment

• 105 JET, serial number range D082000 to G960499
• 115, 6 cylinder, serial number 5314656 and up
• V135, serial number range A904646 to C100860
• V135, serial number range C100861 to C239552
• V135, serial number range C239553 to D081999

Replaces (OEM)

• Mercury Marine 96455A9

Frequently Asked Questions

What engines does the Sierra 18-5798-1 trigger assembly fit? The Sierra 18-5798-1 trigger assembly fits Mercury 105 JET outboards (serial number D082000 to G960499), 115 horsepower 6 cylinder outboards (serial number 5314656 and up), and V135 outboards across serial number ranges A904646 to C100860, C100861 to C239552, and C239553 to D081999.

Is the 18-5798-1 trigger assembly an OEM Mercury part? No, it is a Sierra-brand replacement built as a direct equivalent to Mercury Marine part number 96455A9, so it installs and functions the same as the original factory trigger assembly.

How much does the trigger assembly weigh? The Sierra 18-5798-1 trigger assembly weighs 0.37 pounds.

What is the trigger assembly made of? It is made of durable aluminum, suited to the engine mount environment of an outboard powerhead.

What color is the Sierra 18-5798-1? The trigger assembly is white.

Can I use this trigger assembly on a 6 cylinder outboard? Yes, the 18-5798-1 is compatible with 6 cylinder outboard engines, including the 115 horsepower 6 cylinder application with serial number 5314656 and up.

What fuel type is this trigger assembly designed for? It is designed for gasoline-fueled outboard engines.

Is this trigger assembly rated for saltwater use? The recommended use for the Sierra 18-5798-1 is fresh water applications.

What horsepower range does the 18-5798-1 support? The trigger assembly supports outboard engines up to 225 horsepower.

How is the trigger assembly installed? The Sierra 18-5798-1 is an engine mount trigger assembly, meaning it mounts directly to the outboard engine as part of the ignition system.

How many trigger assemblies come in the package? Each order includes one Sierra 18-5798-1 trigger assembly.

Does the 18-5798-1 fit the V135 outboard? Yes, the V135 is covered across three serial number ranges: A904646 to C100860, C100861 to C239552, and C239553 to D081999.