High Thread Pro

Coil-on Plug

Service Proedure - Removal

Tools Neccessary:

• Thin wall 9/16” spark plug socket, various length extensions and ratchet. (Do not use a standard deep well socket)
• Beam or dial style torque wrench, (non clicking type).
• Carbon dissolving carburetor cleaner.
• Compressed air and blow gun.
• Shop Vacuum.
• Nickel Anti-Seize.

IMPORTANT: Please read carefully to prevent breaking spark plugs during removal. Engine must be completely cold (room temperature) before beginning.

Spark Plug Removal

1. Remove coil on plug assemblies and set aside. Using compressed air and shop vac, clean spark plug wells of all dirt and debris.
2. Using a ratchet, back out each spark plug 1/8 to 1/4 of a turn. Fill the spark plug well with carburetor cleaner to just above the hex on the spark plug. (1/2 to 1 teaspoon) (see illustration #2)
3. Allow a minimum of 30 minutes soak time for the carb cleaner to wick down to the ground electrode shield and soften the carbon deposits at this time.
   NOTES: Review the product label on the carburetor cleaner and adhere to all precautionary statements. Use at room temperature with appropriate PPE, (personal protective equipment).
4. Tighten and then loosen the spark plugs working them back and forth to remove. Use the beam style torque wrench and do not exceed 33ft. lbs. removal torque (see illustration #3). If more than 33ft. lbs. is required; place an additional 1/2 teaspoon of carb cleaner in the well and wait another 15-30 minutes for the carbon to dissolve.
5. Repeat the back and forth effort working the spark plug loose. Some screeching and high effort will be noticed. Remove the spark plugs.
6. Using the shop vac and a small hose, clean out the plug well and combustion chambers of excessive carb cleaner.
   WARNING: Excessive carburetor cleaner in the combustion chamber can cause the engine to hydro lock, remove as much as possible.

Spark Plug Installation

1. New plugs should be installed using a thin film coating of high temperature nickel anti-seize on the ground electrode shield. DO NOT coat the ground strap. (see illustration 4)
2. Tighten spark plugs to 25 lbs.

If you have any questions regarding your Autolite spark plugs, call Autolite Answers(SM) to consult with one of our technicians. Autolite Answers 855-200-5200

Distributorless Ignition System (DIS)

1. Carefully remove the spark plug wires. Grasp the plug wire boot, twist about one-quarter turn to break the seal, then lift straight off. Use plug boot pullers if the boot doesn't break free easily. Number plug wires with tape as you remove them to avoid crossing them. (illus. 1)
2. Loosen each spark plug so it can be removed. Clean the seat area with a blast of compressed air or with a shop vac, use proper PPE. This prevents dirt from falling into the combustion chamber when the old plugs are removed. (illus. 2)
3. Remove the plugs and line them up in cylinder order. Inspection of the firing ends of the plugs can identify a number of engine problems that may need correction. (illus. 3)
4. Check and set the gap on new plugs as recommended in your owner's manual or a Spark Plug Catalog. Use a round feeler gauge to measure the gap between the center and ground electrode. The gauge should pass through snugly but easily. If it's too loose or too tight, reset the gap.
5. Screw new plugs in by hand until tight. . Use a torque wrench to tighten the spark plugs following the manufacturer's recommendations, or refer to a torque chart in the Spark Plug Catalog. If you don't have a torque wrench, see the bottom of the torque chart for hand tightening recommendations.
6. Replace spark plug wires in the correct order. Before installing the wires put a small amount of dielectric grease inside the spark plug boot. Check to see if the boots are brittle or cracked, and if there is corrosion on the connector inside the boot. If any of these conditions are present, the spark plug wire should be replaced.
7. Start the engine. If it misfires or idles roughly, the wires are crossed or not connected to the plugs correctly. Check the firing order and connections closely.

If you have any questions regarding your Autolite spark plugs, call Autolite Answers(SM) to consult with one of our technicians. Autolite Answers 855-200-5200