Service Bulletin I-2 Generator Fiber Idler Gear Breakage

GENERATOR FIBER IDLER GEAR BREAKAGE

The generator fiber idler gear fails when there is no back lash between the generator gear and the fiber gear. There-fore, when replacing a fiber gear, make sure there is back lash between the two gears before assembling the cam
case cover.

TO CHECK FOR BACK LASH IN THE GEARS

1. Assemble and tighten generator in position with three screws, using spacing washers in place of cam case cover.
2. Feel for back lash — gears must have slight movement.
3. When no movement is present, there are three ways to get gear tooth clearance:
   1. With three screws drawn up snug, raise generator to uppermost position and tighten screws. (Check for back lash.)
   2. Reduce the diameter of the screws, as per sketch, which will allow generator to be raised to obtain proper gear mesh.
   

3. Increase the size of the three generator screw holes in the crankcase and cam case cover from 21/64″ to 23/64″ so the generator can be moved to obtain proper gear mesh or back lash.
NOTE: It may be necessary to perform operations #1 and #2.

After the cam case cover is assembled on, hold the generator in uppermost position and tighten three generator mounting screws.

The back lash may be rechecked by removing the band on the generator and reaching in and feeling for back lash by rocking the armature back and forth.

Inspect replacement or original idler gears — when there is clearance at fiber gear to steel gear locking pin — redrill pin holes so the pin fits line to line in both gears.