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Northern Lights 844 / 844L Engine

Name: Northern Lights 844 / 844L Engine
Brand: Northern Lights

The Northern Lights 844 / 844L is a 2.22 L 4-cylinder natural engine rated at 1800 rpm. It powers generator sets from Northern Lights, including the M20CRW3, M844, M844DW3 and M844LW3. It holds 8.2 L (2.2 gal) of oil and 5 L (1.3 gal) of coolant.

Also known as: 844 / 844L, Lugger 844 / 844L

Part of the Northern Lights 844 engine family — 2 variants share parts & fitment.

2.216 L

Displacement

Cylinders

1800 rpm

Rated speed

8.2 L

Oil capacity

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Procedures Wiring

Engine specifications

Oil capacity	8.2 L
Coolant capacity	5.0 L
Displacement	2.216 L
Cylinders	4
Aspiration	Natural
Rated speed	1800 rpm

Generator sets powered by this engine

Northern Lights M20CRW3 Northern Lights M844 Northern Lights M844DW3 Northern Lights M844LW3Northern Lights M844LW3G Gem seriesNorthern Lights M844W3Northern Lights M844W3 with 2011 base frameNorthern Lights ML844 Northern Lights NL844W2

How to read your Northern Lights engine serial & model number →

Common problems

Temperature gauge shows temperature above 205°F (97°C)
Fix: Shut off the engine immediately. Use the Trouble Shooting Guide on page 21 to isolate the cause of the overheat.
Starter inoperative
Cause: Loose or corroded connections
Fix: Clean and tighten loose battery and harness plug connection
Starter cranks slowly
Cause: Batteries too small, Battery cables too small, Crankcase oil too heavy
Fix: Check specific gravity of each battery, Replace battery if necessary, Check electrolyte level of each battery, If low, fill cells with distilled water, Fill with oil of appropriate viscosity
Shutdown is activated and temperature gauge shows within normal range
Fix: Check the engine crankcase oil level. If low, fill with recommended lubricating oil and restart. Watch the oil pressure gauge carefully and shut off the engine if it does not show a normal reading (20-60 PSI) after a few seconds of operation. If the oil level is normal, DO NOT restart the engine. Call your dealer for assistance.
Low battery output
Cause: Sulfated or worn out batteries, Loose or defective electrical system ground wire
Fix: Check specific gravity of each battery, Check electrolyte level of each battery, Repair or replace
Lack of engine power
Cause: Engine overloaded, Intake air restriction, Clogged primary fuel filter element, Clogged secondary fuel filter element, Improper type of fuel
Fix: Reduce load, Service air cleaner, Clean or replace filter element, Replace filter element, Consult fuel supplier and use proper type of fuel for operating conditions
Entire electrical system does not function
Cause: Faulty connection, Sulfated or worn out batteries
Fix: Clean and tighten battery and harness plug connections, Check specific gravity and electrolyte level of each battery
Engine runs irregularly or stalls frequently
Cause: Below normal engine temperature, Clogged primary fuel filter element, Clogged secondary fuel filter element, Water or dirt in the fuel system, Dirty or faulty injection nozzles, Air in fuel system, Improper type of fuel
Fix: Remove and check thermostat, Clean or replace filter element, Replace secondary filter element, Drain, flush, fill and bleed system, Have your dealer check injection nozzles, Inspect clamps and hoses on suction side of fuel pump for air leak, Consult fuel supplier and use proper type of fuel for operating condition
Engine overheats
Fix: See 'Engine Overheats' in next category
Engine hard to start or will not start
Cause: Improper starting procedure, No fuel, Low battery output, Excessive resistance in starting circuit, Crankcase oil too heavy, Improper type of fuel, Water, dirt or air in fuel system, Clogged primary fuel filter element, Clogged secondary fuel filter element, Dirty or faulty injection nozzles
Fix: See starting section of this manual. Take special note of Bypass Switch operation, Check level of fuel in fuel tank, Check electrolyte level and condition, Clean and tighten all battery connections, Use oil of proper viscosity, Consult fuel supplier and use proper type of fuel for operating condition, Drain, flush, fill and bleed system, Clean or replace filter element, Replace filter element, Have your dealer check injection nozzles
Dirty or faulty injection nozzles
Fix: Replace injectors. Best done by dealer
Below normal engine temperature
Cause: Improper valve clearance
Fix: Reset valves. Best done by dealer
Battery will not charge
Cause: Loose or corroded connections, Sulfated or worn out batteries
Fix: Clean and tighten battery connections, Check specific gravity of each battery, Check electrolyte level of each battery
Temperature rises above 205°F (96°C) on Marine units
Fix: Repeat troubleshooting
Shutdown is activated and the temperature gauge shows temperature within normal temperature range
Fix: A. Check the engine crankcase oil level b. If the oil level is low, fill with recommended lubricating oil and restart. Watch the oil pressure gauge carefully and shut off the engine if it does not show a normal reading (20-60 PSI) after a few seconds of operation. c. If the oil level is normal, DO NOT restart the engine. Call your dealer for assistance.

Compiled from service & troubleshooting documentation across every generator set that uses the Northern Lights 844 / 844L.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	Element cannot be cleaned; replace when necessary		24-20001	100 hr	Amazon $184.36 eBay
Fuel filter			24-50002	500 hr	Amazon eBay
Oil filter			24-03100	250 hr	Amazon eBay $23.45
Battery	Add distilled water to manufacturer's recommended level; clean terminals with water and baking soda solution		—	100 hr
Belt	Tension correct when belt depresses about 3/16 in. (5 mm) at midpoint between crankshaft and alternator pulleys		—	100 hr
Coolant	50% water / 50% ethylene glycol antifreeze mix; not methyl alcohol based	5.0	—	2500 hr
Oil	Break-in: Service CC 30 weight oil during first 100 hours; then per lube oil chart	8.2 L	—	250 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Battery electrolyte	Check	50 hr		First service — After first 50 hours and every 50 hours (SP18)
Cylinder head bolts	Adjust	50 hr		First service — Re-tighten head bolts after first 50 hours (see pg. 14)
Engine oil	Change	250 hr		First service — SP2 - first 50 hours (break-in)
Valve clearances	Adjust	50 hr		First service — After first 50 hours (SP6)
Valves	Adjust	50 hr		First service — After first 50 hours (SP6)
Batteries	Check	100 hr		Batteries, cables and cable terminals should be checked and cleaned every 100 hours
Batteries, cables and cable terminals	Clean	100 hr		Clean corrosion with water and baking soda solution; tighten and grease terminals
Battery electrolyte level	Check	100 hr		SP17 - every 100 hours
Battery terminals/cables	Clean	100 hr		Clean corrosion, tighten and grease terminals
Electrolyte level in batteries	Check	100 hr		SP18
Radiator (industrial only)	Clean	100 hr		EVERY 100 HOURS (SP16); check and clean radiator fins
V-belt tension	Check	100 hr		First service — SP5 - daily per SP-5 text, 100 hours on chart
Battery condition	Check	200 hr		SP18 - check condition with hydrometer every 500 hours (chart row 200 hours)
Battery condition	Test	200 hr		Check condition; hydrometer check every 500 hours
Condition of batteries	Check	200 hr		SP19
Engine oil and filter	Change	250 hr	12 mo	First service — Then every 200 hours
Air cleaner	Check	250 hr		SP4; more often in dusty conditions
Batteries	Test	250 hr		Check condition of batteries with hydrometer
Batteries state of charge	Check	600 hr		Hydrometer check (SP19)
Batteries state of charge	Test	250 hr		Check condition with hydrometer (SP19)
Lube oil filters	Change	250 hr		First service — SP3; also at 100 hours then every 250 hours
Radiator fins	Clean	250 hr		Check and clean radiator fins (SP15)
Exhaust elbow	Check	500 hr		SP16
Exhaust elbow	Inspect	500 hr		Sooner if needed; replace if rust or damage
Exhaust system	Inspect	500 hr		Inspect condition of exhaust system (SP22)
Primary fuel filter element	Change	500 hr		SP8 - or as often as necessary; immediately if bowl fills with water
Primary fuel filter element (Racor)	Change	500 hr		SP8; as often as necessary
Raw water pump impeller	Change	1000 hr		SP15 - or as needed
Raw water pump impeller	Replace	500 hr		Or as needed
Secondary fuel filter	Change	500 hr		SP9 - every 500 hours
Cooling system	Clean	2500 hr	12 mo	EVERY 600 HOURS or every 12 months, whichever comes first; check and flush (SP14)
Impeller (seawater pump, marine)	Change	600 hr		EVERY 600 HOURS or as needed (SP17)
Air cleaner element	Change	1000 hr		SP4 - every 1000 hours
Impeller in raw water pump	Change	1000 hr		SP17; or as needed
Injectors	Check	1000 hr		SP12 - clean injection nozzles every 1500 hours
Valve clearance	Adjust	1000 hr		SP6 - after 1000 hours or as needed
Valve clearance	Check	1000 hr		SP6 - also adjust after 1000 hours or as needed
Valve clearances	Check	1000 hr		SP6
Fuel nozzle	Clean	1500 hr		EPA emission standard: fuel nozzle cleaned every 1500 hours
Injection nozzles	Clean	1500 hr		EPA emission standards; nozzles cleaned every 1500 hours, nozzle and pump cleaned/adjusted/repaired every 3000 hours

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Coolant level below filler cap sealing surface	about 1 in. (2.5 cm)	in / cm	engine cold
Clearance	Enclosure left hand side and rear distance from vessel bulkheads (minimum)	4	in
Clearance	Enclosure left hand side and rear distance from vessel bulkheads (recommended)	6	in
Clearance	Heat rejection to jacket coolant (M844K2)	1018	BTU/min	60 Hz
Clearance	Heat rejection to jacket coolant (M844LK2)	1273	BTU/min	60 Hz
Clearance	Panel perimeter clearance (minimum) around panel perimeter, except bottom of side and front panels	1/32	in
Clearance	Siphon break height above vessel's loaded water line (minimum)	12	in
Clearance	V-belt deflection	3/16	in	at midpoint between crankshaft and alternator pulleys
Gap	V-belt deflection	3/16 in. (5 mm)	in. (mm)	at midpoint between crankshaft and alternator pulleys
Gap	V-belt deflection at midpoint between crankshaft and alternator pulleys	3/16	in
Gap	V-belt deflection at midpoint between crankshaft and alternator pulleys	3/16 in. (5 mm)	in / mm	thumb pressure
Gap	V-belt deflection at midpoint between crankshaft and alternator pulleys	5	mm
Gap	V-belt tension (deflection at midpoint between crankshaft and alternator pulleys)	3/16	in. (5 mm)	thumb pressure
Gap	V-belt tension (deflection at midpoint between crankshaft and alternator pulleys)	about 3/16	in. (5 mm)
Other	Coolant level below filler cap sealing surface (cold)	1	in	engine cold
Other	Coolant level below filler cap sealing surface (cold)	2.5	cm	engine cold
Other	Exhaust Gas Temperature	1022	°F (550° C)
Other	Maximum Exhaust Backpressure	48	in (1219 mm) H2O
Pressure	Compression pressure of cylinder - standard value	more than 2.94	MPa
Pressure	Compression pressure of cylinder - standard value	more than 30	kgf/cm2
Pressure	Compression pressure of cylinder - time to be repaired	less than 2.45	MPa
Pressure	Compression pressure of cylinder - time to be repaired	less than 25	kgf/cm2
Pressure	Coolant filler cap pressure valve release	7	PSI (0.5 bar)
Pressure	Coolant filler cap pressure valve release	approximately 7	PSI (0.5 bar)
Pressure	Coolant filler cap relief pressure	approximately 7	PSI (0.5 bar)
Pressure	Coolant filler cap relief valve	7	PSI
Pressure	Cooling system filler cap pressure valve release	approximately 7 PSI (0.5 bar)	PSI
Pressure	Cooling system filler cap relief	7	PSI
Pressure	Engine oil pressure (minimum)	above 15	PSI
Pressure	Engine oil pressure (normal operating, Series 3-4 panels)	20-60	PSI	after a few seconds of operation
Pressure	Engine oil pressure (normal)	20-60	PSI	after a few seconds of operation
Pressure	Minimum oil pressure	15	PSI	must be above 15 PSI while running
Pressure	Minimum oil pressure while operating	above 15 PSI	PSI	units with Series 3 and Series 4 panels
Pressure	Normal oil pressure	20-60	PSI	after a few seconds of operation
Pressure	Normal oil pressure	20-60 PSI	PSI	after a few seconds of operation
Pressure	Oil pressure	20 - 60	PSI	Normal reading after a few seconds of operation
Pressure	Oil pressure (Series 3 and 4 panels, running)	above 15	PSI
Pressure	Oil pressure (minimum)	above 15	PSI	Series 3 and Series 4 Control Panels while operating
Pressure	Oil pressure (minimum, operating)	above 15	PSI
Pressure	Oil pressure (normal reading)	20 - 60	PSI	after a few seconds of operation
Pressure	Oil pressure (normal)	20 - 60	PSI
Pressure	Oil pressure (operating minimum)	above 15	PSI	engine running
Pressure	Oil pressure shutdown	14.2	psi (1.0 Kg/ccm)
Pressure	Radiator filler cap relief pressure	0.5	bar	approximately
Pressure	Radiator filler cap relief pressure	7	PSI	approximately
Pressure	Recommended pressure cap	12.7	psi (0.9 kg/ccm)
Resistance	Glow plug resistance	under 1	ohm	between terminal and engine block
Resistance	Glow plug resistance (terminal to engine block)	under 1	ohm
Resistance	Glow plug resistance (terminal to engine block)	under 1 ohm	ohm	measured with high quality meter
Speed	Frequency / speed reference	60 Hz (1800 RPM), 50 Hz (1500 RPM)	Hz / RPM
Speed	Frequency 50 Hz	1500	RPM	50 Hz
Speed	Frequency 60 Hz	1800	RPM	60 Hz
Speed	Rated RPM / Frequency	1500 / 50Hz	RPM / Hz
Speed	Rated RPM / Frequency	1800 / 60Hz	RPM / Hz
Speed	Rated speed at 50 Hz	1500	RPM
Speed	Rated speed at 60 Hz	1800	RPM
Temperature	Coolant temperature - maximum (marine sets)	below 200 F (94 C)	F	operating
Temperature	Coolant temperature - normal	167 to 194 F (75 to 90 C)	F	operating
Temperature	Coolant temperature shutdown/overheat	above 205	°F
Temperature	Engine coolant temperature (marine)	below 200	°F

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Coolant	50% distilled water / 50% ethylene glycol antifreeze mix			5.3 liters	Approx. coolant capacity M844K2 1.4 gal (5.3 liter); M844LK2 1.5 gal (5.7 liters); M20CR2 1.3 gal (4.8 liters)
Coolant	50% water / 50% conventional ethylene glycol antifreeze	low silicate			Good year round coolant; do not use methyl alcohol based antifreeze
Coolant	50% water / 50% ethylene glycol antifreeze mix				Recommended as a good year-round coolant
Engine oil	Diesel-rated break-in oil	John Deere pre-packaged or equivalent			Use during the first 100 hours
Engine oil	SAE 5-20W	API Service CC/CD/SF multi-viscosity	below -23°C		Below -10°F (-23°C) multi-viscosity; some increase in oil consumption may be expected
Engine oil	SAE 5W	API Service CC/CD/CE or CC/CD/SF	below -23°C		Below -10°F (-23°C). Multi-viscosity alternative SAE 5-20W.
Engine oil	SAE 5W (single viscosity) / SAE 5-20W (multi-viscosity)	API Service CC/CD/CE or CC/CD/CF	below -23°C		Below -10°F (-23°C)
Engine oil	SAE 5W single viscosity / SAE 5-20W multi-viscosity	API Service CC/CD/CE single viscosity oils; API Service CC/CD/SF multi-viscosity oils	below -23°C		Below -10°F (-23°C); use Service CC 30 weight oil during the first 100 hours
Engine oil	SAE-5W	API Service CC/CD/CE single viscosity	below -23°C		Below -10°F (-23°C) single viscosity
Engine oil	Service CC 30 weight				Use during the first 100 hours (break-in oil); set is delivered with special break-in oil
Engine oil	SAE 10-30W	API Service CC/CD/SF multi-viscosity	-23°C to 0°C		-10 to 32°F (-23 to 0°C) multi-viscosity
Engine oil	SAE 10W	API Service CC/CD/CE or CC/CD/SF	-23°C to 0°C		-10 to 32°F (-23 to 0°C). Multi-viscosity alternative SAE 10-30W.
Engine oil	SAE 10W (single viscosity) / SAE 10-30W (multi-viscosity)	API Service CC/CD/CE or CC/CD/CF	-23°C to 0°C		-10 to 32°F (-23 to 0°C)
Engine oil	SAE 10W single viscosity / SAE 10-30W multi-viscosity	API Service CC/CD/CE single viscosity oils; API Service CC/CD/SF multi-viscosity oils	-23°C to 0°C		-10 to 32°F (-23 to 0°C)
Engine oil	SAE-10W	API Service CC/CD/CE single viscosity	-23°C to 0°C		-10 to 32°F (-23 to 0°C) single viscosity
Engine oil	SAE 15-40W	API Service CC/CD/SF multi-viscosity	above 0°C		Above 32°F (0°C) multi-viscosity
Engine oil	SAE 30W	API Service CC/CD/CE (single viscosity) or CC/CD/SF (multi-viscosity)	above 0°C	8.2 liter	Above 32°F (0°C). Multi-viscosity alternative SAE 15-40W. Crankcase capacity including oil filter 2.1 gal (8.2 liter) for 844k/844Lk.
Engine oil	SAE 30W (single viscosity) / SAE 15-40W (multi-viscosity)	API Service CC/CD/CE or CC/CD/CF	above 0°C		Above 32°F (0°C)
Engine oil	SAE 30W single viscosity / SAE 15-40W multi-viscosity	API Service CC/CD/CE single viscosity oils; API Service CC/CD/SF multi-viscosity oils	above 0°C	8.2 liters	Above 32°F (0°C)
Engine oil	SAE-30W	API Service CC/CD/CE single viscosity	above 0°C	2.1 gal (8.2 liters)	Above 32°F (0°C) single viscosity
Fuel	Grade No. 1 diesel	ASTM D975	below 0°C		Use below freezing and for all temperatures above 5,500 ft (1500 m)
Fuel	Grade No. 2 diesel above freezing 32°F (0°C); Grade No. 1 below freezing and above 5,500 ft. (1500 meters)	ASTM designation D975 for diesel fuels; cetane number minimum of 45; sulphur less than 1% (preferably less than 0.5%)			Do not use domestic heating oils, Class B engine, Class D domestic fuels, Class E/F/G/H industrial or marine fuels, ASTM-D975-60T No. 4-D and higher number fuels
Fuel	Grade No. 2 diesel above freezing 32°F (0°C); Grade No. 1 below freezing and for all temperatures above 5,500 ft (1500 m) altitude	ASTM D975			Low sulphur or ultra low sulphur; cetane number minimum 45. Do not use domestic heating oils, Class B, Class D, Class E/F/G/H industrial or marine fuels, or ASTM-D975-60T No. 4-D and higher
Fuel	No. 1 diesel	ASTM D975	below 0°C		Below freezing and for all temperatures at an altitude above 5,500 ft (1500 m).
Fuel	Grade No. 2 diesel	ASTM D975	above 0°C		Use above freezing 32°F (0°C); cetane minimum 45; sulphur less than 1% (preferably less than 0.5%)
Fuel	No. 2 diesel	ASTM D975	above 0°C		Above freezing 32°F (0°C). Sulphur less than 1% (preferably less than 0.5%); cetane minimum 45.
Other	Rubber lubricant				Applied to inside of short blue silicone hose and to exhaust hole grommet during wet exhaust tube installation

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Adjusting V-Belt Tension adjustment

Check tension and wear on the V-belt daily.
Press on the belt at the midpoint between crankshaft and alternator pulleys; correct tension allows about 3/16 in. (5 mm) deflection.
Loosen the alternator adjusting plate bolt and the alternator mounting bolt.
Pivot the alternator at the mounting bolt as needed.
Tighten the mounting bolt and the adjusting bolt.
Operate engine at low idle speed and recheck belt tension.

Adjusting Valve Clearances adjustment

Tools: Feeler gauge, Wrench

Bring No. 1 cylinder to top dead center on compression stroke.
Align top mark of crank pulley with timing gear case mark.
Loosen lock nut and adjust clearance with adjustment screw.
Clearance on both intake and exhaust valves: 0.008 in. (0.2 mm).
Repeat for each cylinder; adjust each set of valves individually.
Replace rocker arm cover and tighten cover nuts to 5 - 8 ft/lbs.

Retightening cylinder head bolts adjustment

Tools: Torque wrench

Retighten the head bolts after the first 50 hours.
Tighten bolts when the engine is cold.
Loosen the valve cover and remove the rocker arm cover.
Tighten head bolts with a torque wrench in the sequence shown, evenly in 1 or 2 passes.
Tighten to specified torque in final pass.

SP-6 Valve Clearances adjustment

Tools: Feeler gauge, Wrench

Adjust valve clearance after 1000 hours or as needed.
Bring No. 1 cylinder to top dead center on the compression stroke; align top mark of crank pulley with timing gear case.
Remove the rocker arm cover and turn the crankshaft forward and backward to confirm TDC.
Loosen the lock nut and adjust clearance between rocker arm and valve guide with the adjustment screw.
Repeat steps 3 and 4 for each cylinder; adjust each valve set individually.
Replace the rocker arm cover and tighten cover nuts.

Valve Clearance Adjustment adjustment

Tools: Adjustment screw, Lock nut, Wrench

Adjust valve clearance after the first 50 hours of operation and every 1000 hours thereafter.
Valve adjustments should be done after the cylinder head bolts have been re-tightened; engine should be cold and NOT running.
Watch the valves while turning the engine over by hand until the inlet valve starts to open and the exhaust valve starts to close.
Turn the crankshaft one more full turn and adjust the clearance on both valves for this cylinder.
Loosen the lock nut and adjust clearance between the rocker arm and valve guide of both intake and exhaust valves with the adjustment screw.
Clearance on both intake and exhaust valves should be 0.008 in. (0.2 mm).
Repeat steps for each cylinder; each set of valves must be adjusted individually.
Replace the rocker arm cover. Tighten cover nuts to 5 - 8 ft/lbs (0.8 - 2.3 kg/m).

Valve Clearance Adjustment (SP-6) adjustment

Tools: Feeler gauge, Wrench

Adjust valve clearance after 1000 hours or as needed.
Bring No. 1 cylinder to top dead center on compression stroke by aligning crank pulley timing mark.
Remove rocker arm cover and turn crankshaft to confirm TDC.
Loosen lock nut and adjust clearance between rocker arm and valve guide with the adjustment screw.
Repeat for each cylinder; each set of valves adjusted individually.
Replace rocker arm cover and tighten nuts.

Valve clearance adjustment (SP6) adjustment

Readjust valve clearance after first 50 hours of operation and every 600 hours thereafter.
Valve adjustments should be done after the cylinder head bolts have been retightened.
Engine should be cold and NOT running.
Turn engine by hand until inlet valve starts to open and exhaust valve starts to close.
Turn crankshaft one more full turn and adjust clearance on both valves for this cylinder.
Loosen lock nut and adjust clearance between rocker arm and valve guide with adjustment screw.
Repeat for each cylinder; each set of valves must be adjusted individually.
Replace rocker arm cover.

Check glow plugs diagnostic

Tools: D.C. test bulb

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

Checking glow plugs diagnostic

Tools: DC test bulb

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

Glow Plug Testing diagnostic

Tools: D.C. test bulb

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

Shutdowns and Alarms diagnostic

⚠ Do not remove the water fill cap of an overheated engine. Escaping high temperature steam can cause severe burns.

⚠ If the oil level is normal, DO NOT restart the engine; call your dealer.

Engage the preheat switch to check the temperature gauge.
If above 205°F (96°C), use the Trouble Shooting Guide to isolate the cause of the overheat.
Make repairs; restart after the temperature gauge registers below 200°F (94°C).
Watch the temperature gauge regularly and turn off the unit if temperature rises above 205°F (96°C).
If shutdown activates within normal temperature, check exhaust temperature, sea water strainer and impeller.

Shutdowns and Alarms Response diagnostic

⚠ Do not remove the water fill cap of an overheated engine. Escaping high temperature steam can cause severe burns.

Check the temperature gauge; if above 205°F (96°C), shut off the engine immediately.
Use the Trouble Shooting Guide to isolate the cause of the overheat.
Make repairs. Restart the Marine set after the temperature gauge registers below 200°F (94°C).
Watch the temperature gauge regularly and turn off the unit if temperature rises above 205°F (96°C).
If shutdown is activated and temperature is normal, check the engine crankcase oil level.
If oil level is low, fill with recommended lubricating oil and restart; watch the oil pressure gauge.
If the oil level is normal, DO NOT restart the engine. Call your dealer for assistance.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

Voltage	Phase	Connection	Notes
110/190	3	wye	Optional voltages (Wye) (NL844L)
110/220	1	zig zag	Optional voltage (NL844L)
115/230	1	zig zag	Optional voltage (NL844L)
120/208	3	wye	Standard low voltage (NL844L); also listed in optional voltages (Wye)
120/240			Optional voltages (GEN) (NL844L); standard output 1 phase, 1.0 power factor
120/240	1	zig zag	Optional voltage (NL844L)
127/220	3	wye	Standard low voltage (NL844L); also listed in optional voltages (Wye)
139/240	3	wye	Optional voltages (Wye) (NL844L)
220/380	3	wye	Standard high voltage (NL844L); also listed in optional voltages (Wye)
240/416	3	wye	Optional voltages (Wye) (NL844L)
254/480	3	wye	Optional voltages (Wye) (NL844L)
277/480	3	wye	Standard high voltage (NL844L)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Northern Lights 844 family

246

Part #	Description	Category
24-20001	Air filter element (M16C, M20CL)	air_filter
24-22009	Air Filter Element	air_filter
24-23100	Air filter element (marine sets)	air_filter
24-28101	Air Filter Element	air_filter
24-28401	Air cleaner element	air_filter
24-28602	Air Filter Element	air_filter
314531127	Air filter	air_filter
22-78701	High output alternator (40A iso ground) 12V w/ adj. regulator	alternator
080109061	Drive Belt (formerly #080109061)	belt
40-02003	Drive Belt	belt
40-02004	Drive Belt (with 24V/35A alternator)	belt
40-02005	Drive Belt (with 12V/51A and 24V/35A alternators)	belt
40-08601	Drive Belt	belt
40-74500	Drive Belt (formerly #40-74500)	belt
V-BELT-16X1.5	V-belt	belt
22-68304	Brush & Holder Assembly	brush_holder
39-70006	Molded Plastic Case	case
27-38008	SS Exhaust Elbow	elbow
00-35406	Gas/Water Separator	fuel_filter
130306190	Fuel Filter Assembly	fuel_filter
24-50002	Primary fuel filter - complete unit (Racor type water separator)	fuel_filter
24-50012	Primary fuel filter element	fuel_filter
24-50013	Primary Fuel Filter/Separator	fuel_filter
24-50014	Standard Fuel Filter	fuel_filter
24-52020	Secondary fuel filter (spin-on)	fuel_filter
052100280	Gasket*	gasket
052109074	Gasket	gasket
11-13101	Gasket, Thermostat Cover	gasket
11-18602	Gasket, Thermostat Cover	gasket
11-28101	Gasket / Air Intake Cover Gasket	gasket
11-38101	Gasket / Exhaust Manifold Gasket	gasket
110996600	Gasket	gasket
110996860	Gasket	gasket
111147200	Head Gasket (formerly #111147200)	gasket
111147520	Head Gasket; t = 1.4mm	gasket
111996410	Gasket, Rocker Arm Cover	gasket
111996420	Gasket, Rocker Arm Cover	gasket
130326051	Gasket	gasket
130516069	Gasket	gasket
130516089	Gasket	gasket
130996070	Gasket	gasket
130996130	Fuel Lift Pump Mtg. Gasket	gasket
131186110	Gasket	gasket
131296255	Gasket	gasket
131426160	Gasket	gasket
131426200	Gasket	gasket
131426230	Gasket	gasket
135996480	Gasket	gasket
135996550	Mtg. Gasket	gasket
135996600	Gasket	gasket
145996370	Gasket	gasket
145996460	Gasket (earlier)	gasket
145996680	Gasket (formerly #145996460)	gasket
165996110	Gasket	gasket
165996351	Gasket	gasket
165996361	Gasket	gasket
165996510	Oil Fill Neck Gasket	gasket
198996060	Gasket	gasket
198996071	Gasket	gasket
29-08100	Gasket Set - Marine	gasket
314990030	Gasket	gasket
340460170	RW Pump Drive Gear	gear
185366060	Glow Plug - 12 Volt	glow_plug
185366100	Glow Plug - 24 Volt	glow_plug
185366220	Glow Plug 12V	glow_plug
GLOW-PLUG-10	Glow plug	glow_plug
130556750	Pipe	hose
130556760	Pipe	hose
131507450	Injection Line #1	hose
131507460	Injection Line #2	hose
131507470	Injection Line #3	hose
131507480	Injection Line #4	hose
131606620	Return Line	hose
140606701	Oil Line	hose
140606710	Oil Drain Hose	hose
140606720	Oil Pipe (844 & 16C)	hose
145536050	Hose	hose
18-13107	Hose	hose
18-13108	Hose 3/4" ID x 18-1/2"	hose
18-13109	Hose 5/16" ID x 25" / Overflow	hose
18-28101	Air Intake Hose (earlier)	hose
18-28102	Air Intake Hose	hose
18-52007	Hose 1/4" ID x 26"	hose
18-52113	Hose Assembly 1/4" ID x 26-1/2"	hose
18-52205	Hose 1/4"ID x 13"	hose
18-58101	Hose Assembly 1/4" ID x 17" (844)	hose
19-00064	Hose Clamp #64 (for tank mounting)	hose
27-13101	Tube Assembly	hose
25-11216	Impeller	impeller
25-12060	Impeller	impeller
131406360	Fuel Injector	injector
131406480	Injector Assembly	injector
131416170	Nozzle	injector
052400400	O-Ring	o_ring
25-12067	O-Ring, Raw Water Pump Cover	o_ring
140406360	Suction Filter	oil_filter
24-02002	Oil Filter	oil_filter
24-03100	Lube oil filter	oil_filter
00-02003	Wear Sleeve; Repair Type	other_service
00-02004	Wear Sleeve; Repair Type	other_service
00-35400	Water Lift Type Muffler	other_service
00-71614	Grommet 1-5/8"ID x 2-1/4"OD	other_service
00-73146	Lifting Eye	other_service
05-70049	Extrusion, vertical	other_service
05-70051	Extrusion, horizontal, sides	other_service
05-70052	Extrusion, horizontal, ends	other_service
10-12002	Tank Assembly	other_service
110666090	Filter	other_service
12-00031	Capscrew, Hex Head M6 x 1.0 x 25 mm	other_service
12-00712	Capscrew, Hex Head M8 x 1.25 x 25 mm	other_service
12-00751	Capscrew, Hex Head M8 x 1.25 x 16 mm	other_service
130516084	Diaphragm	other_service
14-04803	Hex Nut, Nylock M6 x 1.0	other_service
145506480	Heat Exchanger Element (earlier)	other_service
15-00008	Flat Washer M6	other_service
15-00701	Flat Washer M8	other_service
15-00702	Lock Washer, Helical M8	other_service
185416300	Brush	other_service
185446165	Spring	other_service
185446187	Regulator Assembly	other_service
185446253	Rectifier Assembly	other_service
185846360	Brush Holder Assembly	other_service
185846361	Spring Brush / Brush Spring	other_service
20-18101	Heat Exchanger Element (formerly #145506480)	other_service
21-00010	Bushing, Steel 3/8NPT x 1/4NPT	other_service
21-00135	Bushing, Brass 1/2NPT x 1/4NPT	other_service
21-00701	Flat Washer M8	other_service
21-05404	Male Elbow, 45° Steel 1/4NPT x 1/4-37T	other_service
21-12007	Filler Cap (7 PSI)	other_service
21-12008	Filler Cap	other_service
21-51093	Male Connector, Brass 1/2 NPT x 1/2 HB	other_service
21-52245	Male Elbow, Brass 1/4 NPT x 5/16-45T	other_service
21-65005	Bushing, Steel 1" NPT x 3/8 NPT	other_service
21-70007	Female Swivel, Brass 5/16 HB x 5/16-37T	other_service
21-71042	Female Swivel, Brass 1/2 HB x 1/2-45T	other_service
21-71049	Male Elbow, 90° Steel 1/4NPT x 1/4-37T	other_service
21-71056	Female Swivel, Brass 5/16 HB x 5/16-45T	other_service
21-71093	Male Connector, Brass 3/8 NPT x 1/2 HB	other_service
22-40004	Resistor Kit	other_service
22-40012	Resistor 200 Ohm	other_service
22-40018	Circuit Breaker 10 Amp	other_service
22-40334	D.C. Voltage Regulator, 12V, Adjustable	other_service
22-41060	Diode, 6 Amp 50 Volt / 1000 PIV	other_service
22-42043	Circuit Breaker	other_service
22-42047	Relay, 12 Volt SPDT	other_service
22-44852	12 Volt Bulb	other_service
22-44853	24 Volt Bulb	other_service
22-70048	Diode Harness Addition	other_service
22-70280	Circuit Breaker 80A 240VAC	other_service
22-70300	Circuit Breaker 100A 240VAC	other_service
22-90009	Hour Meter	other_service
23-73106	Bracket	other_service
23-75404	Bracket, Tank Mtg.	other_service
23-78007	TOE BRACKET	other_service
25-12004	Repair Kit	other_service
25-12061	Cam	other_service
25-12062	Wear Plate	other_service
25-12064	Bearing	other_service
27-18301	Siphon Break	other_service
27-31119	Dry Exhaust Flex	other_service
27-31207	Dry Exhaust - Critical Residential	other_service
31-12001	Port Adapter (requires #11)	other_service
31-70001	Adapter, Oil Drain	other_service
31-80002	Female Swivel, 1/4HB x 1/4-37T	other_service
33-82205	Platform Mount	other_service
33-82206	Platform Mount	other_service
33-83106	Platform Mount	other_service
34-70010	Oil Drain Kit Complete	other_service
36-72003	Drain Valve	other_service
36-72005	Male Elbow, Brass 1/4 NPT x 5/16-45T	other_service
37-40013	Hourmeter	other_service
38-08120	Standard spare kit for M844DW3/G	other_service
38-08130	World class spare parts kit for M844DW3/G	other_service
38-08420	Standard Spare Parts Kit - HE	other_service
38-08430	Standard Spare Parts Kit - KC	other_service
38-08700	Standard Spare Parts Kit - HE	other_service
38-08701	World Class Spare Parts Kit - HE	other_service
38-08702	Standard Spare Parts Kit - KC	other_service
38-08703	World Class Spare Parts Kit - HE (KC series row as printed)	other_service
512.00	HEAT EXCHANGER/EXPANSION TANK	other_service
M20CRW3	Northern Lights 20 kW (@ 60 Hz) commercial grade	other_service
M844LW3G	=	other_service
OM844W3		other_service
130506140	Fuel Lift Pump	pump
131017600	Injection Pump Assembly	pump
145017350	Coolant Pump Assembly	pump
25-12057	Raw Water Pump	pump
26-71003	Electric Fuel Pump 12V	pump
26-71004	Electric Fuel Pump 24V	pump
36-72002	Hand Pump	pump
025100008	Seal Washer / Gasket	seal
025100010	Seal Washer	seal
025100012	Seal Washer (Industrial only)	seal
025100016	Seal Washer	seal
052100030	O-Ring	seal
052100050	O-Ring	seal
052100070	O-Ring	seal
052100100	O-Ring	seal
052100150	O-Ring	seal
052100400	O-ring	seal
052109072	O-Ring	seal
052109076	O-ring	seal
052109078	O-ring	seal
052300400	O-Ring	seal
052300600	O-Ring	seal
052300700	O-ring	seal
054109013	O-Ring	seal
120406050	Exhaust Valve Guide Seal	seal
120406070	Intake Valve Guide Seal	seal
131226130	O-Ring	seal
131226180	O-Ring	seal
131227240	O-Ring	seal
16-13101	O-Ring	seal
16-15010	O-Ring	seal
16-70001	O-Ring	seal
16-90001	O-ring	seal
198636160	Oil Seal	seal
198636170	Oil Seal	seal
25-12017	Spline Seal	seal
25-12065	Lip Seal	seal
25-12066	Mechanical Seal	seal
185206082	Stop Solenoid - 12 Volt (Standard Ground)	sensor
185206190	Stop Solenoid - 12 Volt (Isolated Ground)	sensor
185206200	Stop Solenoid - 24 Volt (Isolated Ground)	sensor
185246011	Oil pressure unit	sensor
185816120	Switch Assembly	sensor
185816240	Solenoid Assembly	sensor
22-10003	Water Level Switch / Gauge, Isolated Ground	sensor
22-41016	Pressure Sender, 0-80 PSI, 1/8 NPT	sensor
22-41051	Toggle Switch	sensor
22-42055	Engine Temperature Sender - Single Station	sensor
22-71016	Oil Pressure Sender - Dual Station	sensor
22-71026	Engine Temperature Sender - Dual Station	sensor
22-78745	Overspeed Switch	sensor
22-90007	Preheat / Shutdown - Bypass Switch	sensor
22-90008	Engine Control Switch	sensor
37-10005	Low water level switch	sensor
37-40010	Oil Pressure Gauge, 0-80 PSI	sensor
37-40011	Engine Temperature Gauge, 0-250° F	sensor
37-40012	DC Voltmeter, 12 Volt	sensor
37-40014	DC Voltmeter, 24 Volt	sensor
37-78700	Low oil level switch	sensor
385720110	Engine Temperature Switch 95° C / 203° F	sensor
145206022	Thermostat	thermostat
W673-2		workshop_manual
W843-844-2		workshop_manual

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the oil capacity of the Northern Lights 844 / 844L?

The Northern Lights 844 / 844L engine has an oil capacity of 8.2 liters.

What is the displacement of the Northern Lights 844 / 844L?

The Northern Lights 844 / 844L has a displacement of 2.216 liters with 4 cylinders.

Which generators use the Northern Lights 844 / 844L engine?

The Northern Lights 844 / 844L powers 9 generator set(s), including Northern Lights M20CRW3, Northern Lights M844, Northern Lights M844DW3, Northern Lights M844LW3, Northern Lights M844LW3G Gem series.

How often should you change the oil in the Northern Lights 844 / 844L?

The Northern Lights 844 / 844L oil change interval is every 250 hours.

What is a common problem with the Northern Lights 844 / 844L engine?

A commonly reported issue on generators using the Northern Lights 844 / 844L is: Temperature gauge shows temperature above 205°F (97°C). Fix: Shut off the engine immediately. Use the Trouble Shooting Guide on page 21 to isolate the cause of the overheat..