Northern Lights M673L3G-IP Engine

Tools: Feeler gauge, Wrench

1. Rotate crankshaft to bring No. 1 cylinder to top dead center on compression stroke.
2. Align top mark of crank pulley with timing gear case mark.
3. Remove rocker arm cover and confirm No. 1 valves do not move.
4. Loosen lock nut and adjust clearance with adjustment screw.
5. Set both intake and exhaust valve clearance to 0.008 in. (0.2 mm).
6. Repeat for each cylinder; adjust each set individually.
7. Replace rocker arm cover and tighten cover nuts to 5 - 8 ft/lbs (0.8 - 2.3 kg/m).

⚠ Ambient temperatures above 45 degrees Celsius can irreparably damage the inverter.

1. If inverter fails, shut down gen-set and restart to reset inverter.
2. If operation is not restored, consult Northern Lights customer service.

⚠ Do not run engine with air cleaner removed.

1. Inspect air cleaner every 200 hours; check more often in dusty conditions.
2. If element is dirty, wash in soapy water, rinse, and dry thoroughly.
3. Replace element if necessary.
4. Change air cleaner element every 1000 hours or two years, whichever comes first.

⚠ Keep flames and sparks away from batteries.

Tools: Hydrometer

1. Add distilled water to manufacturer's recommended level.
2. Check and clean batteries, cables, and terminals every 100 hours.
3. Clean corrosion with water and baking soda solution; flush with clean water.
4. Tighten terminals and grease them to inhibit corrosion.
5. Check battery condition with hydrometer every 500 hours.

⚠ Escaping diesel fuel under pressure can penetrate skin; relieve pressure before disconnecting lines.

Tools: Cardboard or wood for leak check

1. Loosen bleed screw A on top of filter.
2. Pump hand primer B on fuel lift pump until pure fuel without bubbles escapes.
3. Tighten bleed screw A.
4. Loosen bleed screw C and pump hand primer until pure fuel without bubbles escapes.
5. If engine does not start, loosen one fuel line at injector and crank until pure fuel escapes; tighten.
6. After engine starts, check for fuel leaks using cardboard.

1. First 100 hours are critical to engine life and performance.
2. Operate under various conditions, particularly heavy loads; 50% load required, 75% preferred.
3. Constantly check engine temperature and oil pressure gauges.
4. Change engine oil and filter at 50 hours.
5. Change oil and filter again at 100 hours, then every 200 hours.

⚠ Overtightening can damage filter element.

Tools: Filter wrench

1. Use a filter wrench to remove old filter and dispose of it properly.
2. Remove and discard old filter gasket; clean mounting surface.
3. Spread thin film of engine oil on new filter gasket.
4. Screw filter on until gasket meets sealing surface.
5. Tighten by hand one-half turn farther; do not overtighten.
6. Fill engine with oil, start engine, check for leakage, stop, wait 3 minutes, and check level.

Tools: Dipstick

1. Check oil level in crankcase with dipstick.
2. Oil level must be in waffled area on stick; never allow below this area.
3. Always add the same viscosity of oil as already in crankcase.
4. Do not remove dipstick when engine is running.

⚠ Open sea-cock before running engine.

1. Flush cooling system every 2500 hours or every 24 months, whichever comes first.
2. Remove expansion tank cap and drain engine block.
3. Leave all drains open.
4. Pour clean water into expansion tank until water from drains is free of discoloration and sediment.
5. Let water drain completely.
6. Close drains and refill with recommended mixture.

Tools: Metal rod

1. Clean heat exchanger core every 24 months, after 2500 hours, or as needed.
2. Drain expansion tank and heat exchanger.
3. Remove heat exchanger end covers and remove core.
4. Clean inside of exchanger core tubes using a metal rod.
5. Flush, inspect, and clean again if necessary.
6. Reassemble, fill cooling system, start engine, and check for leaks.

⚠ Never use flushing oil.

1. Change engine oil and oil filter after 50 hours.
2. Change oil and filter again at 100 hours using recommended oil.
3. After 100 hours, change oil and filter every 200 hours.
4. During intermittent cold weather, change oil every 100 hours or six weeks, whichever comes first.
5. Drain oil through oil change tube, replace cap and tube, and refill with recommended oil.

⚠ Place protection under screwdrivers to avoid damaging pump housing.

Tools: Needle-nose pliers or two screwdrivers

1. Remove pump end cover.
2. Pry out impeller using needle-nose pliers or two screwdrivers.
3. Remove all pieces of failed impeller.
4. Clean inside of housing.
5. Press in new impeller and place sealing washers in outer end of impeller center.
6. Replace cover using new gasket or o-ring.