Spark Plug Tools

Tempest® T556™ Thread Lube & Anti-Seize Compound

Various forms of spark plug thread lube anti-seize have been around for years, but many experience the same application problem: they ball up and are very difficult to spread evenly across the threads. Tempest, the innovator of aviation products, wasn’t satisfied and believed a better solution could be formulated. After many months of development, we believe we have found the solution! We are pleased to introduce Tempest T556 newly formulated spark plug thread lube anti-seize. 

Tempest T556 comes packaged with a brush that applies the lubricant to the threads with a smooth even flow. Tempest T556 doesn’t drip, and more importantly, won’t inadvertently run down on the firing end of the spark plug potentially causing an environment conducive to fouling or even pre-ignition. It stays where you put it and covers like a blanket on the first pass!

Tempest® AT5K™ Aviation Spark Plug Resistance Tester

The Tempest AT5K quickly and accurately checks spark plug resistors and quickly displays the results.

Note: The AT5K only checks resistance values. It does not replace, nor is it a substitute for, other tests required to determine a spark plug’s condition.

To access the battery, remove the rear cover, see Figure 1.

Press the red button (1), see Figure 2. The red test LED (2) will illuminate.
Note: If the battery is low, LED (3) will flash brightly.
The AT5K will automatically turn itself off.

Plug the lead into the socket (4). Touch the lead’s end to the test post (5).
The red LED (2) should extinguish and the green LED (6) should come on.
Clean the lead of the spark plug to be tested well and place it on the test post, see Figure 3.
Touch the test lead to the spark plug center electrode, see Figure 4.

Red LED Only:

  • Make sure a good contact between the plug and test post exists. Check the plug again. If the red LED alone remains on, resistance is above ~ 5000 Ohms.
    Replace the spark plug with a TEMPEST spark plug.

Green LED only:

  • Resistance in new spark plug range — less than ~4000 Ohms.

Red and Green LED’s both on:

  • Resistance in serviceable range — less than ~5000 Ohms.


The AT5K works with all popular aviation spark plugs including TEMPEST HIGH ENERGY electronic ignition spark plugs. It can also be used with unshielded spark plugs.

Auburn, AC, Autolite, Bendix, BG, Champion, TEMPEST®, Electroair UREM37-HE electronic ignition spark plug, Unison, Lodge, Red Seal, Spitfire, T-N-T Manufacturing, FYRAC, Chain-O-Spark, Rummell’s Spark Plugs.

For Unshielded Spark Plugs:

Insert a second lead into the test post. Connect the lead to the spark plug wire terminal. Test the spark plug.


Use standard +/- 2% commercial resistors having the following values to check the AT5K response: 3.5k, 4.5k and 5.5k Ohms. Connect one end of a resistor to test post and the other to the test lead. The following should occur:

  • 3.5k Ohm resistor = green LED only illuminated.
  • 4.5k Ohm resistor = green and red LEDs illuminated.
  • 5.5k Ohm resistor = red LED only illuminated.


Use the information in this booklet to meet training requirements of your Civil Aeronautic Authority, where applicable, concerning use of the AT5K.


  • Disconnect the test lead(s) from the AT5K when not in use.
  • Keep solvents, lacquer thinner, etc. away from the AT5K.
  • Don’t submerge the AT5K in water or liquids.

Excessive resistance causes:

  • Hard starting.
  • Skipping, missing, excessive fuel consumption and pollution.
  • Roughness in turbocharged engines.
  • Roughness during lean of peak operations.
  • Roughness at high altitudes.
  • Spark plug fouling.
  • Engine oil contamination from excessive carbon and unburned fuel entering the crankcase.
  • Unnecessary electrical stress on ignition leads, contact points, capacitors and magnetos.
  • Costly, unnecessary spark plug maintenance.

AT5K means: “At 5000 Ohms” change that plug!
Install Tempest spark plugs with monolithic solid state resistors!
New spark plugs without monolithic resistors may drift out of range even before being entered into service.

Tempest® AA446™ Spark Plug Tray

The new Tempest spark plug tray is constructed of high quality metal protecting the spark plugs from damage. Other trays can be prone to tipping and spilling the spark plugs onto the hangar floor rendering them unusable. The Tempest tray design is sturdy and balanced, reducing the likelihood of tipping, rubber feet on the bottom of the tray help keep the tray in place on metal workbenches and tool boxes.

The tray includes numbered spark plug slots allowing for proper spark plug organization and rotation.

Dimensions are 8″ x 3.5″ x 2.5″
Total height including the handle is 5″