G3408 and G3412 Engines Caterpillar

Spark Plug Adapter

Illustration 1	g00608996

Put liquid soap on seal (2). Put 5P-3931 Anti-Seize Compound on the threads of the adapter (1). Put 5P-3931 Anti-Seize Compound on the threads in the cylinder head (3). Replace the gasket (4) when the spark plug adapter is removed and installed.

(1) Torque for adapter ... 95 ± 7 N·m (70 ± 5 lb ft)

Sensor (Digital Ignition)

Illustration 2	g00609009

(1) Sensor

(2) Air gap

Install the sensor into the cover. Back out the sensor one-half ± one-tenth of a turn. This will create an air gap of the following value. ... 0.71 ± 0.14 mm (0.0280 ± 0.0055 inch)

Hold the sensor in place and torque the locknut to the following value. ... 45 ± 7 N·m (33 ± 5 lb ft)

Spark Plug And Transformer (Altronic Magneto)

Illustration 3	g00609049

(1) Transformer

Refer to the separate illustration for specifications on the transformer.

(2) Torque for the bolts that hold the mounting bracket ... 15 ± 5 N·m (11 ± 4 lb ft)

(3) Secondary wire assembly

(4) Torque for the spark plug ... 30 ± 4 N·m (22 ± 3 lb ft)

(5) Gap of the spark plug ... 0.380 mm (0.015 inch)

(6) Seal Installation.

Install the seal. Make sure that the distance from the top of the adapter tube for the spark plug to the top of the seal is the following value. ... 5.0 ± 1.0 mm (0.20 ± 0.04 inch)

Transformer For Altronic Solid State Magneto

Illustration 4	g00579423

The resistance of the primary coil is measured between the positive terminal (2) and the negative terminal (3) of the transformer. ... 0.1 to 0.2 ohms

The resistance of the secondary coil is measured between the negative terminal (3) of the transformer and the outlet (1) for the high current. ... 4,400 to 6,900 ohms

Transformer Assembly For Altronic Installations

Illustration 5	g00583243

1. Set the gap on the spark plug (2) to the following value.

   ... 0.380 mm (0.015 inch)

2. Install the spark plug and tighten the spark plug to the following torque.

   ... 30 ± 4 N·m (22 ± 3 lb ft)

3. Screw the transformer assemblies (1) onto the spark plugs (2). Make sure that the transformer assemblies are finger tight. Tighten an additional one-eighth turn.

Spark Plug And Transformer (Fairbanks Morse Magneto)

Illustration 6	g00579426

(1) Tighten the bolt that holds the clip to the valve cover base to the following torque. ... 15 ± 5 N·m (11 ± 4 lb ft)

(2) Transformer

The resistance of the primary coil is measured between the positive terminal and the negative terminal of the transformer. ... 0.2 to 0.3 ohms

The resistance of the secondary coil is measured between the negative terminal of the transformer and the outlet for the high current. ... 1650 to 2000 ohms

(3) Copper spacer

(4) Spark plug

Set the spark plug gap to the following value. ... 0.38 mm (0.015 inch)

Installation

1. Set the gap on the spark plug electrodes.

2. Remove the copper washer from the spark plug and install the copper spacer.

3. Assemble the transformer to the spark plug.

   Torque the spark plug and transformer assembly to the following value. ... 47 ± 3 N·m (35 ± 2 lb ft)

4. Assemble the spark plug and transformer assembly. Put this assembly in the adapter.

   Torque this assembly to the following value. ... 38 ± 3 N·m (28 ± 2 lb ft)