0320040 JOHNSON SCREW, Trimtab

Table 1
Required Tools
Qty Pt. No. Description
1 9U-6958 Magneto Test Module Use the 9U-6958 Magneto Test Module for measuring the voltage that is supplied to the spark plug by the magneto. The Operating Manual, NEHS0588 is provided with the tool.Bench testing of the magneto is performed by the manufacturer.Timing of the Magneto to the Engine (Solid State Altronic)
Table 2
Tools Needed Qty
9S-9082 Engine Turning Tool 1
Determine the correct ignition timing for the fuel.
Obtain a fuel analysis.
Enter the data from the fuel analysis into the Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)".
Refer to Engine Performance, LEBQ6483, "G3400 Industrial", "Fuel Usage Guide" or Engine Performance, LEBQ6483, "G3400 Generator Set", "Fuel Usage Guide" or consult with your Caterpillar dealer in order to determine the desired ignition timing.
Illustration 1 g00743058
(1) Flywheel
(2) Opening for the 9S-9082 Engine Turning Tool
Remove the covers for flywheel (1) and opening (2) on the right rear side of the flywheel housing.Note: The magneto has two marks that indicate the rotation of the magneto ("CW" and "CCW"). The magneto also has a pointer that moves clockwise or counterclockwise when the crankshaft is rotated. When you time the magneto to the engine, the pointer must indicate the correct timing mark.
Illustration 2 g00743172
Marks for the direction of rotation and pointer on the magneto
Install the 9S-9082 Engine Turning Tool into opening (2). Turn the crankshaft in the direction of engine rotation until the No. 1 piston is coming up on the compression stroke. Also observe the direction that the pointer on the magneto moves.
Illustration 3 g00735090
Flywheel timing marks
Observe the timing marks on flywheel (1). Turn the crankshaft until the desired timing mark on the flywheel is directly under the pointer for the timing marks on the flywheel.
Remove the 9S-9082 Engine Turning Tool.
Observe the pointer on the magneto.When the desired timing mark on the flywheel is obtained, the pointer on the magneto must be aligned with the appropriate mark.If the pointer on the magneto is not aligned with the appropriate mark, remove the magneto from the engine.
Align the pointer on the magneto with the appropriate mark for the direction of rotation.
Illustration 4 g00743728
Lugs on the magneto's drive tang
Pull the magneto drive away from the magneto drive housing. Align the slots of the magneto drive with the lugs on the magneto's drive tang. Push the magneto drive back into the housing.
Keep the pointer on the magneto aligned with the appropriate mark and install the magneto.
Start the engine. Operate the engine at high idle speed.Note: Do not adjust the timing at low idle because of the timing advance in the magneto.
Attach a timing light to the secondary lead for the spark plug of the number 1 cylinder. Use the timing light to observe the timing marks on the flywheel. If necessary, loosen the bolts for the magneto and rotate the magneto in order to gain the desired timing. When the timing is correct, tighten the bolts for the magneto.
Install the covers for flywheel (1) and opening (2) on the right rear side of the flywheel housing.