Military MEP MEP-804A Generator Set

Tools: feeler gage

1. Remove rocker cover.
2. Ensure all eight retaining plate bolts are tight.
3. Rotate crankshaft until TDC line aligns with timing pointer.
4. Check play in No. 1 intake and exhaust valve push rods.
5. Loosen nut and adjusting screw on rocker arms shown in View A.
6. Insert 0.018 in. (0.45 mm) feeler gage between rocker arm and valve stem.
7. Turn adjusting screw until slight drag is felt, then tighten nut.
8. Rotate crankshaft 360 degrees and adjust remaining rocker arms.

⚠ Take care to avoid entry of dirt or foreign particles in fuel injection pump.

1. Align timing pointer at timing gear case and middle 18 degrees notch on crankshaft pulley.
2. Disconnect injection pipe from delivery valve No. 1 and cap openings.
3. Remove No. 1 plate assembly, valve body, spring, gasket, and valve.
4. Install valve body and tighten to 31 ft-lbs (42.0 Nm).
5. Hold fuel control lever to full fuel position.
6. Loosen four nuts mounting pump and pivot pump body.
7. Operate priming pump while pivoting pump until fuel stops flowing from No. 1 delivery valve.
8. Tighten four nuts to 168 in-lbs (19.0 Nm).

⚠ Take care to avoid entry of dirt or foreign particles in fuel injection pump.

1. Check notched line alignment on pump fixing flange and mounting flange.
2. Align crankshaft pulley TDC mark with pointer.
3. Rotate crankshaft pulley counterclockwise approximately 30 degrees.
4. Disconnect injection pipe from delivery valve No. 1.
5. Remove No. 1 plate assembly, valve body, spring, gasket, and valve.
6. Install valve body and tighten to 31 ft-lbs (42.0 Nm).
7. Hold fuel control lever to full fuel position.
8. Slowly turn crankshaft pulley clockwise while operating priming pump until fuel stops flowing from No. 1 delivery valve.

⚠ Keep body clear of test spray.

Tools: fuel injector tester

1. Attach fuel injector to tester and point into clear container.
2. Open valve and operate lever at one stroke per second.
3. Spray should start at 1706 psi (120 kg/cm2) with well atomized pattern.
4. Turn adjusting screw to obtain starting pressure and spray pattern.
5. Hold pressure at 290 psi (20.4 kg/cm2) below opening pressure.
6. No drops should fall within 10 seconds.
7. Install cap nut and tighten to 25.5 ft-lbs (34.0 Nm).

Tools: multimeter

1. Check battery voltage between alternator terminals BAT and R and ground with master switch in Prime Run Position.
2. Start Gen Set operator and recheck voltage on terminal Pos Bat and ground.
3. Voltage should be 28 + 2 VDC.

Tools: compression gage, adapter

1. Start engine and warm until coolant above 176°F (80°C).
2. Shut down engine.
3. Remove glow plug from No. 1 cylinder.
4. Connect adapter and compression gage to glow plug hole.
5. Turn engine over with starter and record reading.
6. Repeat for each cylinder.

1. Place MASTER SWITCH to PRIME & RUN
2. Push PRESS TO TEST on malfunction indicator panel
3. Ensure all indicator lights lit, then all go out
4. Press BATTLE SHORT press to test light
5. Press AC CIRCUIT INTERRUPTER press to test light

Tools: multimeter

1. Make sure batteries fully charged and cables serviceable.
2. Set multimeter for volts DC as Test A.
3. If voltage indicated, solenoid is defective.
4. Momentarily connect jumper as Test B.
5. Multimeter should indicate battery voltage and starter should crank engine.
6. If no voltage, solenoid defective; if voltage but no crank, starter defective.

⚠ High voltage is produced when generator set is in operation; shut down before maintenance.

Tools: Multimeter

1. Remove VOLTAGE adjust potentiometer.
2. Set multimeter for ohms across two outer terminals.
3. Rotate potentiometer shaft counterclockwise as far as it will go.
4. Connect multimeter between center terminal and either outer terminal.
5. Rotate shaft clockwise at an even rate while observing multimeter.
6. Replace potentiometer if indication changes erratically or does not reach maximum ohms.

⚠ DO NOT operate generator set in enclosed areas unless exhaust is properly vented outside.

⚠ Hot exhaust gases can ignite flammable materials.

1. Provide ducts and vents to outside of building if cooling air supply is inadequate.
2. Make building air intake and outlet openings same size or larger than those on generator set.
3. Install gas-tight metal pipe from exhaust pipe to outside of building.
4. Make exhaust pipe extension short and straight with only one 90 degree bend if needed.
5. Shield exhaust pipe with fireproof material where it passes through a flammable wall.
6. Allow space on all sides for service and maintenance.

⚠ Never start generator set unless properly grounded

1. Insert ground cable through slot on terminal marked GND
2. Connect coupling to ground rod and screw in driving stud
3. Drive ground rod until coupling is just above surface
4. Remove driving stud and install another rod section
5. Install another coupling and driving stud, drive down
6. Repeat until ground rod driven eight feet or deeper
7. Connect clamp and ground cable to ground rod

⚠ Never connect or disconnect load cables while generator set is running

Tools: Terminal nut wrench

1. Shutdown generator set
2. Select required output terminals from Table 1
3. Open output load terminal door
4. Ensure jumper securely fastened between LO and ground
5. Loosen terminal nuts on selected terminals
6. Insert load cable ends through entrance box into studs
7. Tighten load terminal nuts
8. Secure wrench in bracket and close door