Cummins/Onan 1B Series / 1B Series Plant — Governor adjustment
Adjustments
For the Cummins/Onan 1B Series / 1B Series Plant, from the Cummins/Onan operator's manual.
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Before you start
- Do not force the arm down on the shaft so far as to cause the arm to bind on the gearcase.
Procedure
- Loosen clamp screw holding governor arm on governor shaft.
- With governor spring holding arm in open throttle position, insert screwdriver in slot at top end of shaft.
- Turn shaft to the right (clockwise) as far as possible. Hold firmly and tighten lock screw securely.
- Do not force arm down on shaft so far as to cause arm to bind on gearcase.
- Move arm in towards cylinder and note if spring snaps it back to wide open position.
- Adjust speed by turning adjusting nut clockwise to increase speed, or counterclockwise to decrease speed.
Tools required
- screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Cummins/Onan operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.