Mitsubishi S4S-D — Adjustment of Governor
Adjustments · Fuel injection pump governor
For the Mitsubishi S4S-D, from the Mitsubishi service manual.
Applies to: Mitsubishi S4S-D, Mitsubishi S4S engine
Before you start
- These settings can be inspected and adjusted at a designated service shop only.
- Be prepared to operate the engine stop lever manually in anticipation of overrunning.
Procedure
- Inspect and adjust after warm-up so water and oil temperatures reach 70 C.
- Start engine and set speed control lever to low idle; turn low idle speed setting screw to set minimum no-load speed.
- Hold speed control lever at specified maximum speed; adjust governor setting bolt to specified speed.
- Adjust rack/full-load stopper bolt to set rated output position.
- Measure speed variation at load removal and application; adjust governor notches by turning swivel lever adjusting screw.
- Seal each setting bolt.
Tools required
- Flat-head screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- One notch equals a quarter turn and changes engine speed by 3 to 5 revolutions
- Adjusting screw can be loosened by 20 notches (5 turns) from fully tightened
Source: Mitsubishi service 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.