# 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

  

🔄 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

  

🚤 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

  

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

  

📦 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

## Details

- **Price:** 25.0 AUD
- **Vendor:** Sawley's Auto and Marine
- **Tags:** Sawley’s AAM Used Parts – Triggers | Ignition Triggers & Pickup Coils

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 25.00 AUD | In stock |

## Images

- 855746A2 Mercury Trigger | Genuine Used Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/855746a2-mercury-trigger-genuine-used-part)
> Updated: 2026-07-12