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Spark Plug Gap Expansion Tool

$34.50/Each
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Part# 12-03391
MFR Model# ATS483

Overview

This tools expands the spark gap of any massive electrode aviation plug safely and efficently -- with the key word being safely... In the past when you over-gapped a plug, and wanted to expand it back out, you would resort to using a screwdriver, dental pick, or whatever else was on hand. But this was almost a sure way to do damage to the plug. Because you would invariably push the screwdriver between the electrodes, which would cause pressure to the center electrode and risk cracking its ceramic casing. The end result would be either reduced performance or total spark plug failure. Not so with this tool.

Specifications

  • 5.6" long, .375" diameter.
  • Made of Nickel-Cadmium plated tool steel in the USA.

Instructions

  • To use this tool, simply hook it under the outer electrode and apply a bit of downward pressure to gently and safely expand the gap without any contact to the center electrode.

Reviews

Very sturdy and effective. Practice on a spare plug first! There is some finesse required.

Russel L Verified Purchase

Spark Plug GAP Expansion Tool

August 25, 2024

Very easy to use. Be gentle and it doesnt mar the other side of the plug as you pry. Only takes a nudge to adjust.

David Verified Purchase

Spark Plug GAP Expansion Tool

August 14, 2024

Product works but needs more detailed instructions on how to place it

Fred H Verified Purchase

Spark Plug GAP Expansion Tool

June 30, 2024

Great tool. Works well.

Rick B Verified Purchase

Spark Plug GAP Expansion Tool

May 14, 2024

Steve B Verified Purchase

Spark Plug GAP Expansion Tool

August 23, 2023

This tool makes the gapping easy! A simple MUST have tool!

James G Verified Purchase

Spark Plug GAP Expansion Tool

June 28, 2023

Perfect tool for the job.

Emery S Verified Purchase

Spark Plug GAP Expansion Tool

February 23, 2023

This tool is perfect. It’s shaped like an oversized exacto knife. I bought 50 govt surplus plugs that had no gap. This opened them up safely.

Discover A Verified Purchase

Spark Plug GAP Expansion Tool

January 28, 2023

The only tool that works properly for gap checking spark plugs.

Mark S Verified Purchase

Spark Plug GAP Expansion Tool

December 14, 2022

Ridgerunner A Verified Purchase

Spark Plug GAP Expansion Tool

November 21, 2022

Q&A

Please note, Aircraft Spruce Canada's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce Canada assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Will this tool work with the BY style plugs?

The documents indicate it will work on all massive electrode plugs, but no mention of the BY series twin electrode projected core nose units.

Q: Will it work with fine wire?

No, this only works for massive plugs.

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