Northern Lights M668 Generator Set

⚠ Check clearances after first 600 hours, first 1200 hours and every 1200 hours thereafter.

Tools: JDE 81-1 or JDE 83 Flywheel Turning Tool, JDE 81-4 Timing Pin, Feeler gauge

1. Remove rocker arm cover with ventilator tube.
2. Remove plastic plugs from engine timing holes on front of flywheel.
3. Rotate flywheel clockwise with Flywheel Turning Tool until Timing Pin engages timing hole.
4. Position No.1 piston at TDC on compression stroke.
5. Adjust valves marked with X; rotate crankshaft one revolution to bring No.4 (or No.6) to TDC.
6. Adjust valves marked with O.
7. Insert feeler gauge between valve stem and rocker arm and adjust with screw until slight drag.

⚠ Escaping diesel fuel under pressure can penetrate the skin; use cardboard or wood, not hands, to search for leaks.

⚠ Always use a backup wrench when loosening or tightening fuel lines.

Tools: Backup wrench

1. Loosen bleed plug on the fuel filter cartridge.
2. Operate primer pump lever on fuel transfer pump until most air bubbles expelled.
3. Tighten bleed plug.
4. If engine will not start, loosen fuel supply pipe at pump and prime until fuel free of air.
5. Retighten fuel supply line to 22 ft. lb. (30 N·m).
6. If still no start, loosen fuel line at injection nozzle, crank engine until fuel without air flows, tighten to 20 foot lb. (27 N·m).

⚠ Never put additives or flushing oil in crankcase.

Tools: Hand drain pump (optional), Owner-supplied drain hose

1. Change engine oil after first 50 hours, first 100 hours, then every 200 hours.
2. Propulsion with drain pump: remove dipstick, unscrew dipstick tube, insert hand pump, drain by pumping.
3. Generator sets: remove plug from base frame outlet, screw in drain hose, open oil pan valve.
4. Drain oil into suitable container, close valve, remove hose and replace plug.
5. Refill engine with recommended oil.
6. Change oil at any seasonal change in temperature.

⚠ Overtightening can damage filter housing.

Tools: Filter wrench

1. Change lube oil filter every 200 hours.
2. Use filter wrench to remove old filter.
3. Make sure gasket from old filter is removed and discarded.
4. Lubricate rubber gasket on new filter and screw on nipple until gasket meets sealing surface.
5. Using hands only, tighten filter one-half turn farther.
6. Fill engine with recommended oil; start engine and check for leakage.

⚠ Heat exchanged cooled engines only.

⚠ Keep an extra impeller and cover gasket in reserve on-board.

Tools: Water pump pliers

1. Remove pump end cover.
2. Remove impeller with water pump pliers; remove all pieces of a failed impeller.
3. Clean inside of housing.
4. Press in new impeller and place sealing washer in outer end of impeller center.
5. Replace cover using a new gasket.

⚠ Cooling water reaches extremely high temperatures; allow engine to cool and open filler cap carefully.

1. Flush cooling system every 600 hours or yearly with engine stopped and cold.
2. Close the seacock.
3. Remove pressure cap from expansion tank; open cooling system air vent on turbocharger if fitted.
4. Open drains on exhaust manifold and engine block; drain fresh water system.
5. For heat exchanger units, open drain cock at bottom of heat exchanger.
6. Pour clean water into expansion tank until drain water runs clear, then close drains.
7. Fill with recommended coolant mixture and close air vent.
8. Open seacock, start engine, check hoses and connections for leaks.

1. Drain seawater cooling systems completely; shut off sea cocks before opening drain cocks.
2. Drain seawater supply lines and wet exhaust line.
3. Loosen seawater pump cover and drain pump.
4. Check freshwater antifreeze mixture and refill water if necessary.

⚠ Use protective clothing and open filler cap carefully when engine is warm to prevent burns.

1. Check water level in expansion tank; should be about 1 3/4 in. (4-5 cm) below filler cap when cold.
2. Check crankcase oil level with dipstick; keep between the waffled area and the marks.
3. Check fuel tank level and open any fuel valves.
4. Propulsion only: check oil level in the reverse gear.
5. Close seacock, check and clean strainer, reopen seacock.
6. Place battery switch in ON position.

⚠ Do not turn battery switch to OFF while engine is running.

1. Unload generator and run three to five minutes for cool down.
2. Turn Engine Control Switch to off position.
3. Close sea cock and fuel valves.
4. Put battery switch in OFF position.

⚠ Do not crank starter for more than 20 seconds.

1. Hold Shutdown Bypass switch ON and push Engine Control switch to START.
2. Release both switches as soon as engine starts.
3. If engine fails to start, be sure starter has stopped before reengaging.
4. Check gauges often: oil pressure above 29 PSI, DC voltmeter 13-14 volts.
5. Let unit run unloaded three to five minutes warm-up.
6. Do not add full electrical load until engine at maximum operating temperature.

⚠ Do not turn battery switch off while engine is running.

1. Run engine three to five minutes in neutral at 1000 RPM for cool down.
2. Return engine to low idle.
3. Turn key switch counterclockwise as far as possible to stop engine.
4. Close sea cock and fuel valves and put battery switch in OFF position.

⚠ Do not crank starter more than 15 seconds consecutively.

⚠ Never race a cold engine.

1. Put gear control in neutral.
2. Move throttle to full speed position and return to idle.
3. Turn key to first position and check voltmeter for battery condition.
4. Turn key to starting position; release key when engine starts.
5. Run engine at approximately 1000 RPM for 3-5 minute warm-up.
6. Check oil pressure above 15 PSI and water temperature not over 200°F.