Usage:
G398 (73B1-Up),
G399 (49C1-Up)
Introduction
This instruction provides the necessary parts and service information required to replace Stitt plugs with Champion plugs.
Reference: Service Manual.
Parts Required
Installation
Perform this installation with the engine stopped and cool, and the starting system disabled.
G379 Engine Cylinder Positions.
G398 Engine Cylinder Positions.
G399 Engine Cylinder Positions.
Harness Assembly (Shielded).
1. Disconnect and remove 4W6741 Harness Assembly (old harness assembly) from cylinder number 3 spark plug, and replace with new 4W6742 Harness Assembly. The old harness assembly is too short for the new spark plug/transformer assembly.
Connector.
2. Disconnect the ignition wiring harness connector at each cylinder. Remove 4W4958 Spark Plug, 4W5469 Adapter Assembly, and 4W4959 Transformer Assembly (Stitt Plug and Transformer) from all cylinders. Cover the cylinder head openings with a clean rag to minimize the possibility of dirt entering the engine.
9Y3985 Spark Plug.
9Y3986 Transformer.
3. To make the installation of the new 9Y3985 Plugs and 9Y3986 Transformers easier and to insure that the plug and transformer are removed as an assembly, screw the plug into the transformer before installation into the engine.
NOTE: The anode (solid post) is inserted into the opening in the bottom of the transformer.
4. Tighten each spark plug in the transformer to 47 ± 3 N·m (35 ± 2 lb ft).
Spark Plug/Transformer Assembly with Cover.
5. Install a new 9Y3987 Cover over each new spark plug/transformer assembly, by slipping it on over the spark plug end. Slide the cover into place onto the spark plug adapter.
6. Install a spark plug/transformer assembly with cover into each cylinder position. Tighten to 38 ± 3 N·m (28 ± 2 lb ft).
7. Connect the ignition wiring harness connector at each cylinder.
8. Enable the starting system.