Mitsubishi S4S Engine

⚠ 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.

⚠ Valve clearance must be checked and adjusted with engine cold.

Tools: JDE83 or JDG820 Flywheel Turning Tool, JDE81-4 Timing Pin, Feeler gauge

1. Disconnect negative battery terminal.
2. Remove rocker arm cover and crankcase ventilator tube.
3. Remove timing hole plugs; rotate engine to No. 1 TDC compression.
4. Insert JDE81-4 timing pin in flywheel.
5. Check intake and exhaust valve clearances with engine cold.
6. Loosen jam nut and adjust screw until feeler gauge drags slightly.
7. Hold screw, tighten jam nut to 27 N•m (20 lb-ft), recheck clearance.
8. Repeat for remaining valves per 4- or 6-cylinder sequence.

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.

⚠ Do not pry against alternator rear frame.

Tools: JDG1341 belt tension gauge

1. Install JDG1341 belt tension gauge halfway between pulleys.
2. Loosen cap screws B and C.
3. Slide alternator or tensioner bracket by hand to remove slack.
4. Pry outward on alternator front frame or tensioner bracket to stretch belt.
5. Stretch until specified tension is achieved.
6. Tighten cap screws B and C.
7. Run engine ten minutes and recheck used belt tension.

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.

⚠ Explosive release of fluids from pressurized cooling system can cause serious burns.

Tools: D05104ST Tester

1. Remove radiator cap and attach to D05104ST tester.
2. Pressurize cap to 70 kPa (0.7 bar) (10 psi).
3. Gauge should hold pressure for 10 seconds.
4. Retest cap turned 180 degrees to verify.
5. Connect gauge and adapter to radiator filler neck.
6. Pressurize system to 70 kPa and check for leaks.