Northern Lights 843N Engine

Tools: feeler gauge, wrench

1. Adjust after head bolts are retightened; engine cold and not running.
2. Turn engine by hand until valves rock, then one more full turn.
3. Loosen lock nut and adjust clearance with adjustment screw.
4. Set intake and exhaust clearance to 0.008 in (0.2 mm).
5. Repeat for each cylinder; replace rocker arm cover.
6. Tighten cover nuts to 5-8 ft/lb (0.8-2.3 kg/m).

1. Press belt at midpoint between crankshaft and alternator pulleys with thumb.
2. Correct tension allows about 3/16 in. (5 mm) deflection.
3. Loosen alternator adjusting plate bolt and mounting bolt.
4. Pivot alternator at mounting bolt as needed.
5. Tighten mounting bolt and adjusting bolt.
6. Operate engine at low idle and recheck tension.

Tools: Adjustment screw, Lock nut wrench

1. Ensure engine is cold and not running.
2. Turn engine by hand until inlet starts to open and exhaust starts to close.
3. Turn crankshaft one more full turn; align top crank pulley mark with TOP mark.
4. Loosen lock nut and adjust clearance between rocker arm and valve guide.
5. Set both intake and exhaust valve clearance to 0.008 in. (0.2 mm).
6. Repeat for each cylinder individually.
7. Replace rocker arm cover; tighten cover nuts to 5-8 ft/lbs.

⚠ Engine should be cold and NOT running.

Tools: Feeler gauge, Wrench

1. Adjust valve clearance after first 50 hours and every 600 hours thereafter.
2. Do adjustment after cylinder head bolts have been retightened; engine cold and NOT running.
3. Turn engine by hand until inlet valve starts to open and exhaust valve starts to close; turn one more full turn.
4. Loosen lock nut and adjust clearance between rocker arm and valve guide to 0.008 in. (0.2 mm).
5. Repeat for each cylinder; replace rocker arm cover and tighten cover nuts to 5 - 8 ft/lbs.

Tools: D.C. test bulb

1. Loosen the current carrying flat wire between the plus-poles of the glow plugs.
2. Connect a D.C. test bulb between the plus-pole of the battery and the plus-pole of the glow plug.
3. If the bulb lights up, the glow plug is functioning properly.
4. Check all glow plugs and replace any faulty ones.

⚠ Do not remove the water fill cap of an overheated engine; allow to cool and remove slowly with protective clothing.

1. Check temperature gauge; if above 205°F (96°C), remove load and shut off the engine.
2. Use the troubleshooting guide to isolate the cause of the overheat.
3. Make repairs; restart the set after the temperature gauge registers below 200°F (94°C).
4. If shutdown activated at normal temperature, check the engine crankcase oil level.
5. If oil is low, fill with recommended oil and restart, watching oil pressure (20-60 PSI).
6. If the oil level is normal, do not restart the engine; call your dealer.

⚠ Do not run engine with air cleaner removed.

1. Inspect air cleaner every 250 hours; check more often in dusty conditions.
2. Replace element if necessary.
3. Ensure no impurities enter engine while changing element.
4. Do not run engine with air cleaner removed.

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

Tools: Hydrometer

1. Check electrolyte level every 50 hours or once per month; 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 a hydrometer every 600 hours.

⚠ Escaping diesel fuel can penetrate skin; use cardboard or wood to search for leaks.

Tools: wrench

1. Loosen bleed bolt A on top of filter.
2. Pump hand primer B until pure fuel escapes; tighten A.
3. Loosen bleed screw C; pump until pure fuel escapes; tighten C.
4. If engine will not start, loosen one fuel line at injector while cranking.
5. Tighten connection when pure fuel escapes; do one line at a time.

⚠ Escaping diesel fuel under pressure can penetrate skin.

Tools: Cardboard or wood for leak check

1. Loosen bleed bolt A on top of filter.
2. Pump hand primer B on fuel lift pump until pure fuel escapes.
3. Tighten bleed screw A.
4. Loosen bleed screw C; pump hand primer B until pure fuel escapes.
5. Tighten bleed screw C.
6. If engine does not start, loosen one fuel line at injector and crank until pure fuel escapes.
7. Tighten connection; repeat one line at a time.
8. After start, use cardboard to check for fuel leaks.

⚠ Escaping diesel fuel under pressure can penetrate skin causing serious personal injury.

⚠ Use cardboard or wood, not hands, to search for suspected leaks.

Tools: Wrench

1. Loosen bleed bolt A on top of the filter.
2. Pump hand primer B on fuel lift pump until pure fuel without bubbles escapes from bleed bolt A; tighten A.
3. Loosen bleed screw C; pump hand primer B until pure fuel escapes; tighten C.
4. If engine does not start, loosen a fuel line at the injector while cranking until pure fuel escapes; tighten connection.
5. After engine starts, use cardboard to look for fuel leaks.

⚠ Dispose of waste oil in an approved manner.

Tools: filter wrench

1. Drain oil when engine is warm; replace drain cap and tube.
2. Remove old oil filter; discard old gasket and clean mount face.
3. Oil new filter gasket; install and tighten one-half turn by hand.
4. Refill with recommended oil; start engine and check for leaks.
5. Stop engine, wait 3 minutes, and check oil level.