Northern Lights M6140AL Engine

Tools: Breaker bar, 19mm or 3/4 inch socket, Feeler gauge

1. Turn off battery switch.
2. Remove valve covers held by three bolts.
3. Rotate crankshaft clockwise to align damper mark with pointer according to data plate.
4. Adjust valves marked X.
5. Loosen crosshead lock nut, then adjustment screw.
6. Tighten adjustment screw until it contacts valve stem, then 20° more.
7. Set intake clearance .017 in (.43mm); exhaust .031 in (.80mm), cold.
8. Rotate engine one revolution; adjust valves marked O.

⚠ Escaping diesel fuel under pressure can penetrate skin.

1. Loosen vent plug in top of fuel filter housing.
2. Unscrew hand primer knob on injection pump and pull up.
3. Operate hand primer until air bubbles expelled and clear fuel escapes.
4. Push hand primer down and tighten.
5. Tighten vent plug.
6. If engine will not start, loosen fuel pipes at injectors.
7. Crank with throttle full until fuel without air flows.
8. Tighten connections.

⚠ Overtightening can damage filter housing.

Tools: Filter wrench

1. Use filter wrench to remove old filter.
2. Remove and discard old filter gasket.
3. Lubricate new filter rubber gasket.
4. Screw filter on until gasket meets sealing surface.
5. Tighten one-half turn farther by hand only.
6. Fill engine with recommended oil.
7. Start engine; check for leakage.
8. Stop engine; check oil level and add oil if needed.

⚠ Cooling water is extremely hot; allow engine to cool before working.

1. Stop engine and allow it to cool.
2. Close sea cock before working on cooling system.
3. Remove filler cap with caution.
4. Open cooling system air vents.
5. Drain jacket water circuit and raw water circuit.
6. Pour clean water into filler until drains run clear.
7. Close drains, re-drain and refill with coolant mixture.
8. Close vents, open sea cock, start engine and check for leaks.

⚠ Keep spare impeller and cover gasket onboard.

Tools: Two screwdrivers

1. Remove pump end cover.
2. Pry out impeller using two screwdrivers with protection under them.
3. Remove all pieces of failed impeller.
4. Clean inside of housing.
5. Press in new impeller; place sealing washers in outer end.
6. Replace cover using new gasket.

1. Press belt with thumb at midpoint between crankshaft and alternator pulleys.
2. Correct tension allows about 3/8 in. (10mm) deflection.
3. Replace belts in pairs if one requires replacement.

1. Drain seawater cooling systems completely; shut sea cocks first.
2. Drain seawater supply lines and wet exhaust line.
3. Loosen seawater pump cover and drain pump.
4. Check freshwater antifreeze mixture; run engine to circulate.
5. Fill fuel tank and add biocide.
6. Seal air cleaner inlet, exhaust, crankcase breather and fuel tank vent.
7. Change crankcase oil and filter; loosen drive belts.
8. Disconnect and clean battery; clean outside and apply corrosion preventative.

⚠ Battery gas can explode; keep flames and sparks away.

1. Check electrolyte level; add distilled water if necessary.
2. Use booster and main batteries with same voltage rating.
3. Connect positive booster terminal to positive main terminal.
4. Connect negative booster terminal to engine block ground.
5. Remove booster battery after starting engine.

⚠ Do not crank starter more than 20 seconds.

1. Hold Shutdown Bypass-Preheat switch ON; push Engine Control switch to START.
2. Release both switches as soon as engine starts.
3. Do not crank starter more than 20 seconds.
4. Cold weather: preheat 30 seconds before starting.
5. Let unit run unloaded for a three to five minute warm-up period.
6. Do not add full electrical load until normal operating temperature.

⚠ Never race a cold engine.

1. Place gear control in the neutral position.
2. Move throttle control to full speed position and return to idle.
3. Turn key to first position; check voltmeter.
4. Cold weather: hold preheat 20-30 seconds.
5. Turn key to starting position; release key as soon as engine starts.
6. Move throttle up until engine runs at approximately 1000 RPM.
7. Do not crank starter more than 20 seconds consecutively.

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

1. Run a three to five minute cool-down period.
2. Propulsion: neutral at 1000 RPM, then low idle.
3. Generators: unload.
4. Push STOP button until engine completely stops.
5. Turn key switch OFF.
6. Close sea cock and fuel valves.
7. Place battery switch OFF.

1. Install new o-ring in injector groove.
2. Install new copper seat on injector end.
3. Insert injector aligning fuel inlet holes.
4. Install new fuel inlet connector.
5. Install hold down, ballwasher and bolt; torque to 48 ft lbs (6.75 kgm).
6. Torque inlet connector to 27 ft lbs (3.8 kgm).
7. Torque lock nut to 29 ft lbs (4.0 kgm).
8. Install injector lines; torque fuel line nuts to 17-18 ft lbs (2.3-2.5 kgm).
9. Bleed fuel system, start engine, check for leaks.