CONVERSION AR 3V2991 - Caterpillar

Turn cam (20) until the high point of the cam is against arm (24) of the contact points. Adjust the gap for the contact points to 0.43 mm (0.017 inch).
Illustration 16 g00997148
Adjust the magneto edge gap by rotating assembly (5) until the keyway is in an UP position, then turn the shaft approximately 15° in the direction of the magneto, as shown.
Illustration 17 g00997151
Loosen screws (25).
Install a 2.39 mm (0.094 inch) diameter rod (27) in timing hole (26) until the rod makes contact with the rotor shaft. Timing hole (26) is used for magnetos with counterclockwise rotation. Turn the rotor shaft clockwise, the direction opposite normal rotation, until rod (27) locks between the rotor pole shoe and the housing field.
With the rotor shaft in position, move the plate to the right or left until the contact points start to open. Tighten screws (25). Note: Use a timing light in order to find the point when the contacts open.
Illustration 18 g00997152
Place distributor disc (28) in position on shaft (1). Install the screw and the lockwasher for distributor disc (28).
Illustration 19 g00997155
Install key (30) and place hub assembly (29) in position on the rotor shaft.
Illustration 20 g00997173Note: The coil of spring (33) must be in the correct direction for magneto rotation. For counterclockwise rotation, the coil of the spring must be in a clockwise direction from end (32).
Place spring (33) in position in coupling shell (31).
Illustration 21 g00997784
Place spring end (32) in position in the groove .
Turn shell (31) counterclockwise one turn, as shown. Push the shell and the hub assembly together. Install the washer and the nut that hold the shell in position.
Illustration 22 g00997177Note: Install the open portion of the vent cap in the DOWN position when you install the magneto on the engine.
Install two screens (35) and vent cap (34) on each side of end cap (36).
Illustration 23 g00997178
Connect grounding wires (37) to end cap (36).
Illustration 24 g00997180
Place the gasket and end cap (36) in position and connect grounding wire (37), coil wire (38), and the wire for the condenser to the contact points.
Fasten end cap (36) to the housing with four lockwashers and the screws.
Illustration 25 g00997181
Install brush and spring assemblies (40) in block assembly (39). The brushes must move freely in the block.
Place grommets (41) in position in cover (42).
Install block assembly (39) on cover (42) with the ground terminal in the DOWN position, as shown.
Illustration 26 g00997183
Place the gasket and cover (42) in position and connect grounding wire (37) to the terminal on block (39). Fasten cap (42) to the end with four lockwashers and the screws.
Remove the nut from end cap (36).
Illustration 27 g00997184
Check the adjustment of the brush spring by measuring the clearance between block (39) and the distributor disc with drill rod (43). The minimum clearance is 4.76 0.80 mm (0.187 0.032 inch). Add gaskets under end cap (42) in order to increase the clearance. Use "Number 10" washers between block (39) and end cap (42). This will decrease the clearance.
Test the performance of the magneto on a test bench. End