Northern Lights 984K Engine

Tools: feeler gauge, wrenches

1. Warm the engine to 167 F - 185 F (75 C - 85 C), then shut off fuel and battery.
2. Rotate the crankshaft clockwise to set cylinder No. 1 at TDC (notch "TDC" aligns with pointer, No. 4 valves rock).
3. Measure clearance on the valves shown adjustable at No. 1 TDC.
4. Loosen the lock nut and turn the adjustment screw until the feeler gauge slides with a slight drag.
5. Tighten the lock nut and recheck the clearance.
6. Rotate the crankshaft one full turn to set cylinder No. 4 at TDC and adjust the remaining valves.
7. Replace the rocker arm cover.

⚠ Shut off fuel and battery before adjustment.

Tools: Feeler gauge, Wrench

1. Warm engine to 167°F - 185°F (75°C - 85°C); shut off fuel and battery.
2. Rotate crankshaft clockwise to set cylinder No. 1 at top dead center.
3. Confirm No. 4 valves rock and TDC notch aligns with pointer.
4. Measure intake clearance 0.006 - 0.009 in. (0.15 - 0.25 mm).
5. Measure exhaust clearance 0.013 - 0.016 in. (0.31 - 0.41 mm).
6. Loosen lock nut and adjust screw until feeler gauge slides with slight drag.
7. Tighten lock nut and recheck clearance.
8. Rotate crankshaft one full turn to set No. 4 at TDC; adjust remaining valves.

Tools: hand primer, wrenches

1. Bleed air from the fuel system.
2. Remove the fuel injection line from the No. 1 delivery valve on the injection pump.
3. Pressurize the system with the hand primer pump.
4. Slowly rotate the crankshaft clockwise by hand until fuel just begins to rise in the No. 1 delivery valve.
5. The crankshaft pulley notch for 14 degrees BTDC should align with the timing pointer; if not, the pump needs to be timed.

⚠ Do not clean filter with diesel fuel, solvent, or gasoline.

⚠ Do not run engine with air cleaner removed.

1. Remove plate on bottom of air intake manifold.
2. Remove and inspect foam element.
3. Wash dirty element in soapy water; rinse and dry thoroughly.
4. Reinstall element and plate.

⚠ Escaping diesel fuel under pressure can penetrate skin; relieve pressure before disconnecting lines and use cardboard or wood, not hands, to search for leaks.

Tools: wrenches, cardboard

1. Loosen the bleed nipple on top of the fuel filter.
2. Pump the hand primer on the fuel lift pump until pure fuel with no bubbles escapes.
3. Tighten the bleed nipple.
4. If the engine still will not start, loosen a fuel line at the injector and crank until pure fuel escapes, then tighten; do each line one at a time.
5. After starting, use cardboard to check for fuel leaks.

⚠ Overtightening can damage filter housing.

Tools: Filter wrench

1. Remove old filter with filter wrench and dispose properly.
2. Remove and discard old gasket; clean mount face.
3. Spread thin film of engine oil on new filter gasket.
4. Screw filter on until gasket meets sealing surface.
5. Tighten one-half turn farther by hand only.
6. Fill engine, start and check for leaks; stop, wait 3 minutes, check oil level.

⚠ Never use a flushing oil or additives in the crankcase.

⚠ Dispose of waste oil in an approved manner.

1. Change oil and filter after the first 50 hours; use Service CC 30 weight oil during the first 100 hours.
2. Change oil and filter again at 100 hours, then every 100 hours.
3. In intermittent cold weather, change every 100 hours or six weeks, whichever comes first.
4. Change oil when the engine is warm but not hot.
5. Loosen clamp on the oil change tube, remove cap, drain oil, replace cap and tube.
6. Refill engine with recommended oil; capacity with new oil filter is 2.4 gallons (9.0 liters).

⚠ Overtightening can damage the filter housing.

Tools: filter wrench

1. Change the lube oil filter every 100 hours.
2. Use a filter wrench to remove the old filter and dispose of it in an approved manner.
3. Remove and discard the old gasket; clean the mount face.
4. Spread a thin film of engine oil on the new filter gasket and screw it on until the gasket meets the sealing surface.
5. Using hands only, tighten the filter one-half turn farther.
6. Fill the engine with recommended oil, start and check for leaks; stop, wait 3 minutes and recheck level.

⚠ Be sure to open the sea-cock after working on the cooling system and starting the engine.

Tools: metal rod

1. Clean the heat exchanger core once a year or after 2400 hours of operation; close the sea-cock.
2. Drain the expansion tank and heat exchanger.
3. Remove the heat exchanger end covers.
4. Clean the inside of the core tubes using a metal rod; flush and inspect, cleaning again if necessary.
5. Reassemble, fill the cooling system, start the engine and check for leaks.

⚠ Close sea-cock before working on cooling system.

⚠ Open sea-cock after working on cooling system before starting.

1. Remove fill cap and open drains on engine block.
2. Pour clean water into engine until water runs clear of discoloration.
3. Close drains and refill with 50% water / 50% ethylene glycol antifreeze.
4. Check hoses and connections and repair any leakage.
5. Start engine, check for leaks, run five minutes, then shut down.
6. Let engine cool and check coolant level; add as needed.

⚠ Cooling water reaches extremely high temperature; allow the engine to cool and open the filler cap carefully with protective clothing.

1. Flush every 600 hours or every 12 months, whichever comes first; close the sea-cock first.
2. Remove the fill cap and open the drains on the engine block.
3. Pour clean water into the engine until water from the engine is clear of discoloration.
4. Close the drains and refill with 50% water / 50% ethylene glycol antifreeze mix.
5. Check hoses and connections and repair any leakage.
6. Start the engine, run five minutes, shut down, let cool and recheck coolant level.
7. Open the sea-cock after working on the cooling system.

⚠ Never use a flushing oil.

1. Change oil when engine is warm but not hot.
2. Loosen clamp on oil change tube, remove cap, and drain oil.
3. Replace cap and tube.
4. Refill engine with recommended oil.