TM 10-3930-671-24 Governor Adjustment The  function  of  the  governor  is  to  limit  the  maximum speed of the engine to: 1. Protect the main hydraulic pump. 2. Limit the maximum travel speed of the truck. 3. Prevent runaway or excessive engine rpm. Normally,   adjustment   of   the   governor   is   not   required. The  correct  no-load  governed  speed  setting  adjustment is  made  at  the  factory  and  the  governor  sealed  before shipment.    The  seal  should  not  be  broken  unless  it  is necessary,   e.g.,   during   engine   overhaul.      When   the governor is replaced or readjusted, install a new seal.  All operators  should  be  instructed  not  to  break  the  seal  to tamper with the governor. When  engine  speed  is  increased  from  idling  speed  by pushing on the accelerator pedal quickly, slight variations ("hunting") in engine speed may occur.  This should not be considered an abnormal condition requiring governor adjustment. NOTE • Be careful in making adjustments when  the  engine  is  operated  at high speeds. • Be sure that the drive wheels are raised   off   the   floor,   or   blocked securely to prevent movement. • Return all controls to NEUTRAL. • Apply the parking brake. Preliminary Service Preparations 1. Open and remove both side doors and raise the seat deck.  Be sure that the seat deck support is securely latched. 2. Connect   a   tachometer,   or   a   combination   test instrument. Governor Adjustment Procedures 1 - Maximum Speed Setting CAUTION Under  no  circumstances  should  the engine   be   allowed   to   operate   at   a higher     speed     than     is     specified. Severe   damage   to   the   engine   may result. NOTE When fitting a replacement fuel pump, or in the event of maximum     speed     screw     having     been     moved,     the maximum no-load speed must be checked and re-set, as necessary. The   maximum   no-load   speed   will   vary   according   to application.  For details, reference should be made to the code number stamped on the fuel pump data plate.  The last   four   numbers   un   the   code   indicated   the   speed setting required, e.g., 2600 rpm in following example: Code Example: --AS62/800/02600 2 - Idle Speed Setting The  engine  idling  speed  is  adjusted  by  the  idle  screw. With the engine warm and running, turn the screw clock- wise  to  increase  engine  speed  and  counterclockwise  to decrease idle speed. F-110