Clarke — Governor speed adjustment (droop and speed)
Adjustments · Mechanical governor / fuel injection pump
From a Clarke operator's manual — check it applies to your exact model before use.
Applies to: Perkins 1000 Series engine
Procedure
- Droop adjustment: rotate the set screw on the rear of the governor counter clockwise until it stops (do not use excess force).
- If the required speed is between 1470 RPM and 1900 RPM turn the set screw clockwise one full turn; if between 2100 RPM and 3000 RPM turn it 4-1/2 times clockwise.
- Speed adjustment: start and warm up the engine, then loosen the jam nut.
- While observing the instrument panel tach, rotate the long adjustor clockwise to lower RPM and counter clockwise to raise RPM until the desired speed is obtained.
- Hold the long adjustor securely with a wrench and tighten the jam nut, then stop the engine.
Tools required
- standard screwdriver
- wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Crank terminate SW#1 set to 1000 RPM
- Overspeed SW#2 set to 120% of rated speed, max 3300 RPM
Full service-parts list: Perkins 1000 Series engine →
Source: Clarke 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.