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Ullman Universal Spark Plug Gap Gauge

$2.15/Each
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Part# 12-21375
MFR Model# SG-2 INCHES

Overview

Provides easy accurate spark plug adjustment. Features flanged edge for electrode bend- ing and beveled round hole for opening gap. 1.5" dia. Wt.: 0.8 oz. Scaled from .020" to .100". Pewter plating makes the inches more legible for user to read. Also available in metric scale (0.5 mm to 2.4 mm).
   
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Reviews

Ed M Verified Purchase

Ullman SG-2 Spark Plg GAP Tool

April 29, 2022

Nice Gap tool for strait gap adjustment. For all the other gap adjustment I got the wire gap tool. Good to have both.

Lewis M Verified Purchase

Ullman SG-2 Spark Plg GAP Tool

April 8, 2022

Very inexpensive, simple, well made, I use it as a preliminary gap checker. Edge gets progressively thicker along the circumference with thickness markings. Plug electrodes can be placed between the edge, then the device is rotated until mild resistance is felt. The gap can then be read. The surface of the device is a template against which the negative electrode can be pressed to reduce the gap, but this is crude. Better to confirm the gap with a wire style gap checker, make adjustments with a thumb screw device made for that purpose.

Gary
March 18, 2021

I have used these for years but couldnt find replace ments for old ones I had. After years of use my old ones were wearing so the were not accurate anymore and the hardware store I bought them at no longer carries them. These appear identical I gapped a plug for my SR500 and checked the gap with feeler gauges and it was spot on.

Mike D
May 21, 2020

Simple, effective, cheap, weighs nothing and fits in any tool kit.

John C
January 14, 2018

Not very clean, upon receiving.

Bob S Verified Purchase

Ullman SG-2 Spark Plg GAP Tool

June 18, 2024

Unfortunately the min gap it can measure is .020 and my plugs are gapped at .014-.018.

Casey M Verified Purchase

Ullman SG-2 Spark Plg GAP Tool

July 6, 2021

Q&A

Please note, Aircraft Spruce'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 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: Is the center region of the gap gauge empty or is there an Ullman logo?

The center of the gap gauge is blank.

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