855746A2 Mercury Trigger | Genuine Used Part

🔧 Product Description

Genuine Used Mercury Mariner Four-Cylinder CDM Short-Arm Trigger - Part Number: 855746A2

A genuine pre-owned Mercury and Mariner five-wire trigger assembly for selected four-cylinder 80 Jet, 100HP, 115HP and 125HP two-stroke engines.

This short-arm timer-base trigger supplies crankshaft-position information to the CDM ignition system and rotates with the spark-advance linkage.

⚙️ Key Features

• Genuine Mercury or Mariner used trigger
• Correct OEM reference 855746A2
• Four-cylinder CDM ignition configuration
• Five-wire short-arm assembly
• Suitable for selected 80 Jet and 100HP through 125HP engines
• CDI and Sierra replacements available

🚤 Compatibility

Commonly used on selected

• Mercury 80 Jet
• Mercury 100HP
• Mercury 115HP
• Mercury 125HP
• Compatible Mariner four-cylinder engines

Representative fitment

• 80 Jet from applicable 0G-series serial ranges
• 100HP through 125HP from applicable 0G760300-and-later ranges
• Representative production period: Approximately 1996-2006

Important fitment note

• Confirm the engine is a four-cylinder CDM model.
• Compare the five-wire connector and short advance arm.
• It is not interchangeable with three-cylinder trigger 855746A1.
• Serial-number verification is essential.

🔌 Function

The trigger sends timed crankshaft-position pulses to the CDM ignition modules.

Rotation of the trigger assembly changes ignition advance according to throttle position.

⚠️ Common Signs of Failure

• No spark on one or more cylinders
• Intermittent spark loss
• Difficult starting
• Engine stalls when warm
• Misfire under load
• Engine will not reach rated rpm
• Timing does not advance correctly
• Trigger wiring rubs under the flywheel
• Electrical output is outside specification

🛠️ Service Notes

Recommended checks before installation

• Confirm all five wires and terminals
• Check the short-arm configuration
• Test trigger resistance and output
• Inspect CDM modules and stator
• Check flywheel magnets and key
• Confirm smooth timing-arm movement
• Set maximum timing after installation

🔄 Supersession & Cross Reference

OEM Supersession / Related Chain

• 834821T - Earlier or related trigger
• 854513T - Related service trigger
• 855746A2 - OEM assembly reference
• 855746A21 - Related service-kit reference
• 855748A2 - Related OEM trigger reference

OEM / Related Numbers

• 855746A2
• 855746A21
• 855748A2
• 854513T
• 834821T
• Trigger Type: Four-Cylinder CDM Short Arm
• Wiring: Five-wire configuration

Aftermarket / Verified Equivalents

• CDI Electronics: 134-4513-4
• Sierra: 18-99415
• Aftermarket replacement for 834821T / 854513T
• Aftermarket trigger replacing 855746A2 / 855748A2

📦 Condition

• Genuine Mercury or Mariner used part
• Pre-owned electrical component
• Wire ageing and cosmetic wear may be present
• Electrical testing before installation is strongly recommended
• Supplied in protective or equivalent packaging