Mitsubishi S4S-D — Break-in Operation (Overhauled Engine)
Operation
For the Mitsubishi S4S-D, from the Mitsubishi service manual.
Applies to: Mitsubishi S4S-D, Mitsubishi S4S engine
Procedure
- Check coolant, engine oil and fuel levels; bleed fuel and cooling systems.
- With fuel supply cut off, crank engine about 15 seconds to circulate oil.
- Move speed control lever slightly toward increased fuel and start engine.
- Run at minimum no-load speed.
- Operate per the break-in load/time schedule.
- After break-in, check bolts and nuts for looseness, adjust valve clearance, inspect fuel injection timing.
Tools required
- Dynamometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Lubricating oil pressure 0.29 to 0.49 MPa (3 to 5 kgf/cm2) [43 to 71 psi] at 1500 min-1 or over
- Coolant temperature 75 to 85 C [167 to 185 F]
- Lubricating oil temperature 70 to 90 C [158 to 194 F]
- Break-in schedule: 1000 min-1 no load 30 min; 1500 min-1 25% 30 min; rated speed 2300 min-1 25% 10 min; 50% 10 min; 75% 30 min; 100% 20 min
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.