12V Cummins Governor Lever Adjustment

Here is the ins and outs of the secret governor lever adjustment

This is a cut away view of the governor of a P7100 pump. Notice how the lever hit the cam plate flush at the very bottom edge. To check your adjustment the throttle lever needs to be moved until the lever just touches the cam plate. With the AFC housing removed, look down through the opening behind the cam plate and see where the lever is striking the plate. This should be done with the Fuel Shutoff Solenoid in the run ( or pulled up ) position.

Where the lever strikes the cam plate will vary depending on the style and design of the cam plate you are using. For plates similar to the stock plate, like shown below, this lever is set correctly. It is adjusted so the lever is flush with the bottom edge of the plate, and does not ride under the plate.

(Picture Courtesy of BD Power)

For cam plates, like a TST #6 for example, that have a taper at the very bottom of the plate, adjust the lever so the lever hits at the tip of the bottom nose on the plate. It is OK to be slightly below that. However too far down causes the lever to be held back as the RPM’s rise. This causes the loss in bottom end power, with the sudden surge as the lever finally clears the nose and hits the main fueling curve.

This is what the pump looks like from the back with the cover removed. Do not change the adjustment in the upper right hand corner. The adjustment in the lower left hand corner is the one to make. Loosen the locknut ( 10mm socket required ). Making very small adjustments to the screw, adjust the lever the proper height. Now tighten the locknut.

One thing to realize about the plate is that it is properly called a full load throttle stop. What this means is that if you are not running at WOT or close to it the plate is not doing anything. It’s just taking up space in the pump.

[thanks to piersdiesel.com used by permission]