Mitsubishi S4S-D Generator Set

⚠ Inspect and adjust when the engine is cold.

Tools: Feeler/thickness gage

1. Insert a thickness gage between rocker arm and valve cap to check clearance.
2. Loosen the lock nut.
3. Tighten or loosen the adjusting screw until the gage moves slightly stiff.
4. Tighten the lock nut firmly and check clearance again.
5. Adjust other cylinders while turning the engine.

1. If fuel is injected earlier than normal, turn the fuel injection pump away from the crankcase.
2. If fuel is injected later than normal, turn the fuel injection pump toward the crankcase.

⚠ 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.

Tools: Flat-head screwdriver

1. Inspect and adjust after warm-up so water and oil temperatures reach 70 C.
2. Start engine and set speed control lever to low idle; turn low idle speed setting screw to set minimum no-load speed.
3. Hold speed control lever at specified maximum speed; adjust governor setting bolt to specified speed.
4. Adjust rack/full-load stopper bolt to set rated output position.
5. Measure speed variation at load removal and application; adjust governor notches by turning swivel lever adjusting screw.
6. Seal each setting bolt.

1. Inspect the V-belt for deflection when pressed with the thumb at the center of its span.
2. Loosen all bolts securing the alternator.
3. Tilt the alternator at an appropriate angle to adjust tension.
4. Retighten the bolts.

Tools: Turning socket 58309-73100

1. Engage the turning socket with the crankshaft pulley nut and turn in the normal direction.
2. Stop when the \"0\" mark on the crankshaft pulley aligns with the pointer on the timing gear case.
3. Move the rocker arms of inlet and exhaust valves of No.1 cylinder to check pushrods do not push them up.
4. If pushrods push up rocker arms, rotate crankshaft another turn.

Tools: Thickness gage

1. Make the valve clearance of cylinder No.1 inlet and exhaust valves 3 mm using a flat plate.
2. Insert the thinnest thickness gage (0.05 mm) between valve cap top face and rocker.
3. Turn the crankshaft slowly.
4. Find the position where the gage is caught tight (valve begins to open) and where it begins to move (valve closed).
5. Check these positions coincide with the valve timing chart.

Tools: Tester (multimeter), Soldering iron

1. Perform continuity test on each rectifier diode.
2. Inspect field coils for continuity between slip rings and between slip ring and shaft.
3. Inspect stator core for continuity between leads and between each lead and core.
4. Measure brush length and replace if at or below limit.
5. Remove brush and spring by unsoldering the brush lead; push new brush into holder and solder lead.

⚠ Do not wash the overrunning clutch in wash oil.

Tools: Dial gage, Spring balance, Growler

1. Inspect brushes for wear and measure brush length.
2. Measure brush spring load with a spring balance.
3. Inspect brush holders for grounding and looseness.
4. Measure commutator radial runout and outside diameter; measure mica undercutting.
5. Test armature coil for short circuit, grounding and open circuit.
6. Inspect field coil for continuity and grounding.
7. Check bearings rotate smoothly.
8. Inspect overrunning clutch and pinion.
9. Inspecting front and rear brackets, internal/planetary gears and lever.
10. Inspect magnet switch and starter relay.

Tools: Turning socket 58309-73100, Spare injection pipe

1. Bring No.1 piston to top dead center.
2. Remove delivery valve holder from No.1 plunger; remove delivery valve, spring and stopper; install delivery valve holder alone.
3. Install spare injection pipe to No.1 plunger with other end downward.
4. Position crankshaft about 60 deg before TDC of No.1 piston on compression stroke.
5. Feed fuel by priming pump and slowly turn crankshaft allowing fuel to flow from the pipe.
6. Slowly turn further when flow is about to stop; stop when flow stops.
7. Check the line on the crankshaft pulley and pointer indicate the fuel injection timing.

⚠ Measure all cylinders; do not assume condition from one cylinder.

Tools: Compression gage 33391-02100, Gage adapter 30691-21100 (swirl chamber), Gage adapter 32491-04100 (direct injection)

1. Move control lever to STOP position.
2. Remove glow plugs from all cylinders.
3. Install gage adapter and compression gage on cylinder being measured.
4. Crank engine with starter and read gage at which needle stabilizes.
5. If measured value is at or below limit, overhaul the engine.
6. Measure all cylinders.

⚠ Using the common gasket (32413-03200) is also allowed if it is difficult to use liquid gasket.

1. Clean the mount surfaces of the crankcase, timing gear case and oil pan.
2. Squeeze Three Bond 1207C liquid gasket in a 4 mm diameter bead all around the oil pan flange and spread it.
3. Install the oil pan within five minutes of applying the liquid gasket.
4. Tighten the mounting bolts to the specified torque.

⚠ Striking the oil seal directly with a hammer causes seal damage and oil leaks.

Tools: Oil seal driver, Oil seal guide

1. Check the seal lip for scratches and damage; position the lip correctly.
2. Apply a small amount of grease to the periphery (housing contact surface).
3. Use an oil seal driver to install straight into the housing.
4. Apply grease to the oil seal lip for shaft installation.
5. Use an oil seal guide over stepped portions, splines, threads or key grooves.