# 393-9459Q1 Aftermarket Mercruiser 4-Cylinder Distributor Cap | Sawley's Select Marine Parts

🔧 Product Description

  

Aftermarket replacement Four-Cylinder Delco Distributor Cap - Replaces Part Number: 393-9459Q1

  

New aftermarket conventional Delco distributor cap replacing MerCruiser 393-9459Q1 for early GM four-cylinder marine engines.

  

⚙️ Key Features

  

• Four-cylinder conventional Delco cap

• Supports 2.5L, 3.0L and 3.7L MerCruiser engines

• Marine-grade corrosion-resistant terminals

• Cross-references early OMC and Mercury cap numbers

• Not interchangeable with later 811635T3 Delco EST cap

  

🧰 Kit / Assembly Contents

  

• 1 × Four-cylinder distributor cap - Part Number: 393-9459Q1

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 393-9459Q1 → Supersedes/cross-references 393-9459, 393-9549T and 33667

• FI6900052 and OMC 380541 (cross-brand related references)

  

OEM / Related Numbers:

  

• 393-9459

• 393-9549T

• 33667

• FI6900052

• 380541

  

Aftermarket / Verified Equivalents:

  

• Sierra: 18-5385

• GLM: 71540

• Mallory: 9-29401

• CDI Electronics: E64-0002

  

🚤 Compatibility

  

Commonly used on:

  

• Early MerCruiser GM four-cylinder distributor ignition systems

  

Typically suits:

  

• Engine / Equipment models:

• 2.5L/120HP GM four-cylinder

• 3.0L/140HP GM four-cylinder

• 3.7L/470-family four-cylinder applications using the conventional Delco cap

• HP / Output Range: Approximately 120HP - 190HP

• Engine / System Type: GM inline four-cylinder petrol marine engine with conventional distributor

• Year Range: Approximately 1963 - 1989, depending on engine family

• Serial / Component Identification: Confirm conventional Delco cap shape; later EST distributors use 811635T3.

  

🔌 Function

  

The distributor cap contains the high-voltage terminals that route ignition-coil output to the correct spark-plug lead. It also insulates the terminals and rotor path from moisture, salt and arcing.

  

Common signs of failure / service requirement:

  

• Crossfire, backfiring or random-cylinder misfire

• Hard starting in damp or humid conditions

• Carbon tracking, burnt terminals or internal arcing

• Cracks, corrosion or green deposits inside the cap

• Rough idle and loss of power under acceleration

  

📦 Condition

  

• New aftermarket replacement part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 38.5 AUD
- **Vendor:** Sawley's Select Marine Parts
- **Type:** Ignition & Controls
- **Tags:** Ignition Components - Mercruiser, Sawley's Select – Ignition Components – MerCruiser | Marine Ignition Parts Coils Modules & Sensors

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 38.50 AUD | In stock |

## Images

- 393-9459Q1 Aftermarket Mercruiser 4-Cylinder Distributor Cap | Sawley's Select Marine Parts

---

> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/393-9459q1-mercruiser-393-9459q1-4cylinder-distributor-cap-replacement)
> Updated: 2026-09-05