• 7452A21 Mercury CDI | Genuine Used Part
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7452A21 Mercury CDI | Genuine Used Part

7452A21 Mercury CDI | Genuine Used Part

$120.00 AUD
$120.00 AUD
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🔧 Product Description

Genuine Mercury Switch Box / CDI Module - Part Number: 339-7452A21

A genuine Mercury ignition switch box / CDI module used on selected Mercury and Mariner 2-cylinder two-stroke outboards. This bullet-connector ignition module controls spark triggering from the stator and trigger circuits to the ignition coils.

⚙️ Key Features

  • Genuine Mercury CDI / switch box
  • Correct Mercury part number 339-7452A21
  • Bullet-connector ignition pack
  • Used on selected 6HP to 35HP 2-cylinder Mercury / Mariner two-stroke outboards
  • Cross-references with CDI Electronics 114-7452K1 and Sierra 18-5776 style replacements

🚤 Compatibility

Commonly used on

  • Mercury / Mariner 2-cylinder two-stroke bullet-connector ignition systems

Typically suits

  • Engine models:
  • Mercury 6HP 2-cylinder - 1980-1997
  • Mercury 8HP 2-cylinder - 1980-1997
  • Mercury 9.9HP 2-cylinder - 1980-1997
  • Mercury 10HP 2-cylinder - 1980-1997
  • Mercury 15HP 2-cylinder - 1980-1997
  • Mercury 18HP 2-cylinder - 1980-1997
  • Mercury 20HP 2-cylinder - 1980-1997
  • Mercury 25HP 2-cylinder - 1980-1997
  • Mercury 35HP 2-cylinder - 1980-1997
  • Mariner 6HP 2-cylinder - 1980-1997
  • Mariner 8HP 2-cylinder - 1980-1997
  • Mariner 9.9HP 2-cylinder - 1980-1997
  • Mariner 10HP 2-cylinder - 1980-1997
  • Mariner 15HP 2-cylinder - 1980-1997
  • Mariner 18HP 2-cylinder - 1980-1997
  • Mariner 20HP 2-cylinder - 1980-1997
  • Mariner 25HP 2-cylinder - 1980-1997
  • Mariner 35HP 2-cylinder - 1980-1997
  • HP Range: 6HP - 35HP
  • Engine Type: Mercury / Mariner 2-cylinder two-stroke outboard ignition system
  • Year Range: approximately 1980 - 1997
  • Serial Note: Match by engine serial number, bullet-connector pack layout and original switch-box number.

🔌 Function

The CDI / switch box stores and releases ignition energy to trigger spark at the correct timing point for the ignition coils.

⚠️ Common Signs of Failure

  • No spark
  • Weak or intermittent spark
  • Engine starts then loses spark
  • Misfire under load
  • Spark returns when a known-good switch box is fitted
  • Heat-related ignition failure
  • Damaged or corroded bullet connectors

🔄 Supersession & Cross Reference

OEM Supersession Chain

  • 339-7452A21 later Mercury switch box reference
  • 339-7452A20 earlier related Mercury switch box reference
  • 339-7452A19 earlier related Mercury switch box reference
  • 339-7452A18 earlier related Mercury switch box reference
  • 339-7452A15 earlier related Mercury switch box reference
  • 339-7452A14 earlier related Mercury switch box reference
  • 339-7452A13 earlier related Mercury switch box reference
  • 339-7452A11 earlier related Mercury switch box reference
  • 339-7452A10 earlier related Mercury switch box reference
  • 339-7452A9 earlier related Mercury switch box reference
  • 339-7452A8 earlier related Mercury switch box reference
  • 339-7452A7 earlier related Mercury switch box reference
  • 339-7452A1 earlier related Mercury switch box reference

OEM / Related Numbers

  • 339-7452A21
  • 7452A21
  • 3397452A21
  • 339-7452A20
  • 339-7452A19
  • 339-7452A18
  • 339-7452A15
  • 339-7452A14
  • 339-7452A13
  • 339-7452A11
  • 339-7452A10
  • 339-7452A9
  • 339-7452A8
  • 339-7452A7
  • 339-7452A1
  • Switch box
  • CDI module
  • Ignition pack

Aftermarket / Verified Equivalents

  • CDI Electronics: 114-7452K1
  • Sierra: 18-5776

📦 Condition

  • Genuine used part
  • Removed from running engine where applicable
  • In good working condition unless otherwise stated

Shipping & Delivery

Flat-rate shipping Australia-wide — $14.99 per order, no matter how many parts you add. Orders dispatch from our Kadina, South Australia store. Need it urgently or want to collect in person? Call us on 0412 532 984 before ordering.

Returns & Warranty

14-day change-of-mind returns — if it's not right or you ordered the wrong part, send it back within 14 days in the condition you received it for a refund or exchange. Full details in our Refunds & Returns policy.

Not sure this fits?

Ask us before you buy — we check part numbers and fitment every day. Call 0412 532 984 (Mon–Fri 8.30am–4.30pm) or message us through the contact page with your engine or vehicle details.

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