Northern Lights L944D, M944W, NL944D2, M30CW, M944T, NL944T2, and... User manual

OL944D
For Model: L944D
OPERATOR’S MANUAL
Marine Generators | Marine Diesel Engines | Land-Based Generators

Diesel engine exhaust and some of its constitu-
ents are known to the State of California to cause
cancer, birth defects, and other reproductive harm.
— CALIFORNIA —
Proposition 65 Warning:
Northern Lights
4420 14th Avenue N.W.
Seattle, WA 98107
Tel: [phone]
Fax: [phone]
Copyright ©2013 Northern Lights, Inc.
All rights reserved. Northern Lights™, and
the Northern Lights logo are trademarks of
Northern Lights, Inc.
Printed in U.S.A.
PART NO.: OL944D 11/13

OL944D 11/13
3
Proprietary Information
This publication is the property of Northern Lights, Inc.
It may not be reproduced in whole or in part without the written permission of Northern Lights, Inc.
© Northern Lights, Inc. All rights reserved. Litho U.S.A. Publication number OL944D 11/13
Read this operator's manual thoroughly before starting to operate your equipment.
This manual contains information you will need to run and service your new unit.
OPERATOR'S MANUAL
for Northern Lights®L944D Diesel
INTRODUCTION ....................................................4
Model Numbers ..................................................4
Serial Numbers ...................................................4
WARRANTY ............................................................5
SAFETY RULES .....................................................5
COMPONENT LOCATIONS
L944D ..........................................................6 - 7
INSTRUMENT PANEL...........................................8
OPERATING PROCEDURES
Break-in Period...................................................9
Before Starting....................................................9
Starting............................................................. 10
Operating ......................................................... 10
Stopping........................................................... 10
Alarms.......................................................10 - 11
Spare Parts ........................................................11
SERVICING SCHEDULE CHART ............ 12 - 13
SERVICING
Lubrication - General....................................... 14
Checking Oil.................................................... 14
Oil Changes ..................................................... 14
Changing Oil Filter .......................................... 15
Air Filter .......................................................... 15
Table of Contents
SERVICING (Continued)
V-Belts ............................................................. 15
Valve Clearances.............................................. 16
Fuels - General................................................. 17
Fuel Filters ....................................................... 17
Bleeding the Fuel System ................................ 18
Injector Service................................................ 19
Injection Pump................................................. 20
Cooling System ............................................... 21
Heat Exchanger................................................ 22
Raw Water Pump ............................................. 22
Zinc Electrodes ................................................ 22
Electrical System - General ............................. 23
Booster Batteries.............................................. 23
Battery Care ..................................................... 24
Winterizing / Out-of-Service ........................... 24
TROUBLESHOOTING
Electrical .......................................................... 25
Engine ...................................................... 26 - 28
SPECIFICATIONS ............................................... 29
WIRING DIAGRAMS
DC Electrical ........................................... 30 - 31

4
OL944D 11/13
The servicing of marine engines and generator sets
presents unique problems. In many cases, boats cannot
be moved to a repair facility. Marine engines cannot be
compared to the servicing of automobiles, trucks, or
even farm equipment. Failures often occur in remote
areas far from competent assistance. Marine engines are
taxed far more severely than auto or truck engines;
therefore, maintenance schedules must be adhered to
more strictly. Failures begin with minor problems that
are overlooked and become amplied when not corrected
during routine maintenance.
As operator, it is your obligation to learn about your
equipment and its proper maintenance. This is not a
comprehensive technical service manual. Nor will it make
the reader into an expert mechanic. Its aim is to aid you in
maintaining your unit properly.
Introduction
L - Lugger Propulsion Engine Model number of engine block
Bore Cylinders
94 mm 4
Serial Numbers
MODEL INCLUDED
This manual covers the operating instructions for:
L944Dpropulsion engine, which use the 944 engine block.
Model Numbers
Model numbers give the unit's application, block model, aspiration, and RPM:
+
Unit Identication
Northern Lights marine diesel generator set with
a 944 engine, naturally aspirated.
L944D
L 944
=
When referencing Northern Lights, Inc. equipment by serial number, please refer only to the number
stamped on the Northern Lights®or Lugger®serial number plate.
Revised page 3-2-10

OL944D 11/13
5
A warranty registration certicate is supplied with your
engine. It entitles the original purchaser of our
equipment to a warranty covering material or assembly
faults. The extent of coverage is described in the Limited
Warranty Statement. We recommend that you study the
statement carefully.
NOTE: If the warranty is to apply, the servicing
instructions outlined in this manual must be followed.
If further information is needed, please contact an
authorized dealer or the factory.
CAUTION: Accident reports show that careless use of engines causes a high percentage
of accidents. You can avoid accidents by observing these safety rules. Study these rules carefully
and enforce them on the job.
• Use caution in handling fuel. Never refuel a hot or
running engine. Do not smoke while lling fuel tank
or servicing fuel system.
• Keep your hands, feet, hair and clothing away from
power-driven parts.
• Check for any loose electrical connections or faulty
wiring.
• Engines should be operated only by knowledgeable,
qualied personnel.
• Look completely around engine to make sure that
everything is clear before starting.
• Do not operate an engine that isn't in proper working
order. If an unsafe operating condition is noted, tag the
set and control panel so others will also know about the
problem.
• Provide rst aid kits.
• Never leave engine without proper security.
• Turn the coolant tank cap slowly to relieve pressure
before removing. Add coolant only when the engine
is stopped and cool.
• Mount a re extinguisher near engine.
• Always disconnect the battery ground strap before
making adjustments.
• Operate engines in properly ventilated areas.
• Keep trash and other objects away from engine.
• Escaping uids under pressure can penetrate your
skin. Use a piece of cardboard or wood, not your
hands, to search for leaks.
• Avoid wearing loose clothing without a belt when
working around engines.
• Do not oil or grease engine while it is running.
• Remove the negative (-) battery terminal cable before
servicing electrical components or welding.
Safety Rules
CAUTION: This symbol is used throughout
this book to alert you to possible danger areas.
Please take special notice of these sections.
Warranty

6
OL944D 11/13
Figure 2: L944DService Side
L944D Component Locations
1. Expansion Tank
2. Coolant Fill
3. Rocker Arm Cover
4. Fuel Filter
5. Relay Board Cover
6. Air Filter
7. Transmission Gear
8. Oil Pan
9. Lube Oil Dipstick
10. Oil Filter
11. Fuel Primer Pump
12. Injection Pump
13. Lube Oil Fill
14. Heat Exchanger Raw Water
Drain and Zinc
15. Thermostat Housing
123 4 56
7
8
11 9
12
13
10
15
14

OL944D 11/13
7
L944D Component Locations
Figure 3: L944DNon-Service Side
15. Wet Exhaust Elbow
16. Exhaust Manifold
17. Heat Exchanger
18. Raw Water Pump
19. PTO Housing
20. Belt Guard
25. Oil Pan
21. Alternator
22. Starter
15 16 13 1
17
18
19
8
20
2
21
22
7
14

8
OL944D 11/13
Instrument Panel
Figure 4: Lugger Main Instrument Control Panel
1. TACHOMETER
The tachometer shows the engine speed in revolutions
per minute. (RPM). Numbers are multiples of 100.
2. HOUR METER
Keeps track of the engine running time.
3. D.C. VOLTMETER
When the engine is stopped, the voltmeter shows the
condition of the battery. When the engine is running,
it indicates the voltage output of the alternator.
4. KEY SWITCH
Turning the key clockwise to the rst position will
switch on the current. Continue turning the key
clockwise to preheat the engine, then again to start the
engine. When the engine starts, immediately turn the
key back to the rst position while the engine is run-
ning.
The key must be kept in the “on” or rst position
while the engine is running. Turn the key counter
clockwise as far as possible to stop the engine.
Note: Optional ybridge panels have engine start switches
instead of key switches.
5. COVER
(Stop button not used for this application.)
6. INSTRUMENT PANEL LIGHTING
The switch turns on the instrument panel lights.
7. OIL PRESSURE FAULT LIGHT
Indicates low oil pressure. Activates in conjunction
with alarm horn.
8. ENGINE TEMPERATURE FAULT LIGHT
Indicates engine is over-heating. Activates in
conjunction with alarm horn.
9. ALARM HORN
Shut down engine if possible and investigate
immediately.
10. WIRE HARNESS
11. COOLANT TEMPERATURE GAUGE
Water temperature gauge shows the temperature of the
engine coolant. If the gauge registers over 2000F or
drops below 1400F, stop the engine and investigate.
12. OIL PRESSURE GAUGE
Shows the oil pressure in the engine lubricating system.
If the pressure drops below 15 PSI at a speed higher
than idling, stop the engine immediately.
12
3
4
5
6
7
8
9
10
11
12

OL944D 11/13
9
Operating Procedures
BEFORE STARTING
1. Check the water level by removing the pressure
cap from the expansion tank. In order to give the
cooling water an opportunity to expand, the level
should be about 1 in. (2.5 cm) below the ller cap
sealing surface when the engine is cold.
CAUTION: Use protective clothing and open
the ller cap carefully when the engine is warm to
prevent burns.
2. Check the oil level in the crankcase with the
dipstick. The oil level must be between high and
low marks on the stick. Never allow the level to go
below this area. Always add the same viscosity of
oil as is already in the crankcase.
3. Check the fuel tank level and open any fuel valves
on the tank and at the secondary fuel lter.
4. Close the sea-cock, check and clean the sea strainer,
and reopen the sea-cock.
5. Place the battery switch in the ON position.
NOTE: The battery switch must always be kept ON
while the engine is running. If the switch is
turned OFF while the engine is running,
the battery charging alternator could be
damaged.
BREAK-IN PERIOD
1. The rst 100 hours on a new or reconditioned
engine are critical to its life and performance.
2. Constantly check the engine temperature and oil
pressure gauges.
3. Oil consumption is greater during break-in as
piston rings take time to seat.
4. Break-In Oil Changes: Change engine oil and
lter at 50 hours. Change oil and lter again at
100 hours (consult Lubricants section for oil
recommendation).
Operating Instructions:
Maintain at least a 75% load on your engine for the
rst 100 hours. If this is not possible, maintain no
less than a 50% load to ensure proper seating of the
piston rings. Vary the load to help seat the rings.

10
OL944D 11/13
5. If the proper propeller is used, the engine should
reach its appropriate maximum RPM’s at full throttle
(2500 RPM). If the maximum rated RPM’s for your
engine application are exceeded at full throttle, then
your propeller is too small. If you cannot reach your
maximum rated RPM’s at full throttle, etiher your
propeller is too large or bottom growth is slowing
the boat.
6. To establish Maximum Cruising RPM: Establish
th RPM at full throttle and subtract 200-300 RPM.
This will promote engine life and reduce fuel
consumption.
SHUTDOWN
1. Run the engine for a three to ve minute cool-down
period in neutral at 1000 RPM.
2. Return engine to low idle.
3. Turn the key switch counter clockwise as far as
possible to stop the engine.
4. Close the sea cock and fuel valves and put the
battery switch in OFF position.
Note: Do not turn the battery switch to OFF while
the engine is running.
ALARMS
1. Your unit is tted with a warning system to indicate
high water temperature and low oil pressure.
Propulsion engines have warning horns to sound and
warn you of a problem.
Note: When the engine is not running the horn will
sound when the key is in the “on” position because
there is no oil pressure.
Do not rely on the alarms to the exclusion of
careful gauge monitoring. Checking the gauges
could prevent damage to the unit and dangerous
power losses.
Operating Procedures
STARTING
1. Put the gear control in the neutral position.
2. Move the throttle control to the full speed postion
and return back to idle.
3. Turn the key switch to the rst position. Check the
voltage meter to see the condition of the batteries.
For starting, the voltmeter should not read below 12
volts. (24 volts for 24 volt systems.)
4. Turn the key to the next position; preheat for 5 to 10
seconds. Then turn the key to the starting position
and as soon as the engine starts, release the key.
Move the throttle up until the engine is running at
approximately 1000 RPM.
5. Do not crank the starter for more than 15 seconds
consecutively. If the engine fails to start with the
rst attempt, be sure that the starter has stopped
completely before re-engaging.
Note: Never race a cold engine. Operate at 1000
RPM for a 3 to 5 minute warm-up period.
OPERATING
1. Check the oil pressure as soon as the engine has
started. Oil pressure must be above 15 PSI. The
engine must never be run if the oil pressure is below
15 PSI.
2. The D.C. voltmeter should read between
13 and 14volts at 60° F (16° C) ambient temperature.
(26 to 28 volts for 24 volt systems.)
3. The water temperature gauge should not rise above
200° F (94° C). If it does, shut down the engine and
investigate the cause of overheating.
4. Do not exceed 800 RPM when shifting marine gear.
Repeated shifts at higher engine speeds can damage
the reverse gear.

OL944D 11/13
11
ALARMS (continued)
2. If the alarm system is activated:
a. Check the temperature gauge, if the temperature
is above 2050F (970C) shut the engine off
immediately.
b. Use the Trouble Shooting Guide on page 25 to
isolate the cause of the overheat.
CAUTION: Do not remove the water ll
cap of an overheated engine. Escaping high
temperature steam can cause severe burns.
Allow the engine to cool and then remove the
cap slowly using protective clothing.
c. Make repairs and restart after the temperature
gauge registers below 200° F (94° C).
d. Watch the temperature gauge regularly and
turn off the unit if the temperature rises above
205° F (96° C). Repeat troubleshooting.
3. If alarm is activated and the temperature gauge
shows temperature within normal temperature range:
a. Check the engine crankcase oil level.
b. If the oil level is low, ll 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 Northern Lights or Lugger
dealer for assistance.
Operating Procedures
SPARE PARTS
1. ADE recommends that you keep the following spare
parts on hand for eld service. The parts are
available from your local Northern Lights dealer.
Some marine models may already have “On-Board
Kits,” a handy box that contains the most common
parts you will need.
a. Primary and secondary fuel lter elements
b. Oil lters
c. Air lter elements
d. Alternator belt
e. Thermostat and gaskets
f. Seawater pump impeller and gaskets
g. Glow plugs
h. Injector and washer
i. Rocker Arm Cover gasket
j. Zinc Anode
k. Relay, SPDT 12 VDC 50 Amp
l. Engine overhaul gasket set
2. If your engine is operating a long distance from a
servicing dealer, add the following:
a. Complete set of injectors
b. Complete set of glow plugs
c. Fuel lift pump

12
OL944D 11/13
The Servicing Schedule Chart below shows the service schedule required for proper maintenance of your generator set.
More detailed coverage of each Service Point (SP) is listed on the page noted in the ‘page’ column.
DAILY:
SP1 Check oil level in engine
SP8 Check primary fuel lter
SP14 Check cooling water level
Check sea strainer
AFTER FIRST 50 HOURS:
SP2/3 Change engine oil and lter
SP5 Check V-belt tension
SP7 Adjust valves
SP19 Check electrolyte level in batteries
EVERY 50 HOURS:
SP5 Check V-belt tension
SP19 Check electrolyte level in batteries
AFTER FIRST 100 HOURS:
SP2/3 Change engine oil and lter
EVERY 250 HOURS:
SP2/3 Change engine oil and lter
SP4 Check air cleaner
SP18 Check zinc electrodes
EVERY 500 HOURS:
SP6 Check valve clearances
SP9 Change primary fuel lter element
SP10 Change secondary fuel lter
SP12 Check injectors
SP15 Check cooling system
SP17 Change impeller
SP20 Check state of charge of batteries
EVERY 2000 HOURS or as needed:
SP13 Check fuel injection pump
SP16 Check and clean heat exchanger
SP24 Inspect starter and alternator
Servicing Schedule Chart
SERVICE 50 100 250 500 2000
POINT PAGE OPERATION DAILY Hours Hours Hours Hours Hours
ENGINE:
SP1 12Check oil level
SP2 12Change engine oil1, 5, 6
SP3 13 Change lube oil lters1, 5
SP4 13Check air cleaner1, 4
SP5 13Check V-belt tension1
SP7 14 Check valve clearances5
FUEL SYSTEM:
SP815 Check primary lter2
SP915 Change primary lter element1, 3
SP10 15 Change secondary fuel lter1, 3
SP1116Bleed the fuel system3
SP1217Check injectors1
SP1318Check fuel injection pump
COOLING SYSTEM:
SP14 20 Check cooling water level
SP15 20 Check and ush cooling system7
SP16 21 Check and clean heat exchanger
SP17 21 Change impeller in raw water pump1, 3
SP18 21 Check zinc electrodes4
ELECTRICAL SYSTEM:
SP19 23 Check electrolyte level in batteries1, 4
SP20 23 Check condition of batteries with hydrometer1
SP24 24 Inspect alternator and starter
OUT OF SERVICE:
SP23 23 Winterizing or out-of-service3
1) Perform all maintenance once a year even if hour level has not been
reached.
2) Consult manufacturer's maintenance schedule, note on chart.
3) Whenever necessary.
4) More often if necessary.
5) After rst 50 hours.
6) Adjust at rst 100 hours.
7) Or every 1 year

OL944D 11/13
13
Service
Point HOURS/ DATE
Service Record
OPERATION
50 HOURS
SP5 Check V-belt tension
SP19 Check electrolyte
in batteries
250 HOURS
SP2 Change engine oil
SP3 Change lubricating oil lters
SP4 Check air cleaner
SP18 Check zinc electrodes
EVERY 500 HOURS
SP7 Check valve clearances
SP8 Change primary lter element
SP10 Change secondary fuel lter
SP12 Check injectors
SP15 Check cooling system
SP17 Change impeller in seawater pump
SP20 Check condition of batteries with hydrometer
2000 HOURS or as required
SP13 Check fuel injection pump
SP15 Flush cooling system
SP16 Check and clean heat exchanger
Service Notes:

14
OL944D 11/13
Servicing
LUBRICATION - GENERAL
1. Use only clean, high quality lubricants
stored in clean containers in a protected area.
2. These lubricants are acceptable:
a. API Service CD, CE, and CF-4 single viscosity
oils.
b. API Service CD, CE, and CF-4 multi-viscosity oils.
3. Use the proper weight oil for your average
operation temperature.
Air Single Multi-
Temperature Viscosity Viscosity
Above 32° F SAE 30W SAE 15-40W
(0° C)
-10° to 32° F SAE 10W SAE 10-30W
(-23° to 0° C)
Figure 5: Lube Oils
4. Never put additives or ushing oil in crankcase.
SP1. CHECKING OIL LEVEL
1. While the engine is stopped, check the oil
level in the crankcase with the dipstick daily.
The oil level must be between the high and low
marks on the stick. Fill with the recommended
oil, and ll only to the high mark on the dipstick.
Follow the lubrication recommendations in
Figure 5.
SP2. OIL CHANGES
1. The set is delivered with special break-in
oil. Change the engine oil and oil lter after
50 hours of operation. Use Service CC30
weight oil during the rst 100 hours.
2. Change the oil and lter again at 100 hours
using the oil recommended in the above
diagram. After this, change oil and lter
every 250 hours.
3. During intermittent cold weather operation,
change oil every 100 hours or six weeks,
whichever comes rst.
4. Change oil at any seasonal change in
temperature when a new viscosity of oil
is required.
5. Change oil when engine is warm but not
hot.
6. Dispose of waste oil in an approved manner.
7. Never use a ushing oil.
8. Loosen clamp on oil change tube. Remove
cap. Drain oil. Replace cap and tube.
9. Rell engine with recommended oil.
10. Engine capacity with new oil lter is:
Model L944D....................2.64 gallons
(10 liters)

OL944D 11/13
15
SP3. CHANGING LUBE OIL FILTER
1. Change the lube oil lter every 250 hours.
2. Use a lter wrench to remove old lter. Dispose of
lter in approved manner.
3. Make sure the gasket from the old lter is
removed and discarded. Clean mount face.
4. Spread a thin lm of engine oil on the rubber
gasket on the new lter and screw it on nipple
until gasket meets the sealing surface.
5. Using hands only – no wrench – tighten lter
one-half turn farther. Overtightening can do
damage to lter housing.
6. Fill engine with recommended oil. Start engine
and check for leakage. Stop engine, wait 3 minutes,
and check oil level. Add additional oil if necessary.
7. Oil lter part number is:
Model L944D.....................................#24-01201
SP4. AIR CLEANER
1. Visually inspect air cleaner every 250 hours. In
dusty conditions, check more often.
2. Remove the cover on the rear of the air intake
manifold. Remove and inspect the foam element.
If dirty, wash element in soapy water. Rinse and
dry thoroughly before reinstalling.
Note: Make absolutely sure no impurities enter
the engine while changing the element, and
do not run the engine with the air cleaner
removed.
  Donotcleanthelterwithdieselfuel,
solvent, or gasoline. Serious engine damage
can result.
SP5. V-BELTS
1. Check the tension and wear on the V-belt after
every 50 hours.
2. Use your thumb to press on the belt at the
midpoint between the crankshaft and alternator
pulleys. The tension is correct if the belt can be
depressed about .39 to .47 in. (10 - 12 mm) with
22 lbs. (10 kg) force.
Servicing

16
OL944D 11/13
Servicing
SP7. VALVE CLEARANCES
1. Readjust valve clearance after rst 50 hours of opera-
tion. Check valves every 500 hours thereafter.
2. Check the valves when the engine is cold.
3. Rotate the crankshaft in a clockwise direction, using
a turning socket, from the front of the engine to bring
the rst piston to the top dead center on the
compression stroke. When the mark on the crankshaft
pulley aligns with the pointer on the timing gear case
stop turning. Make sure the rocker arms of the No. 1
cylinder are loose at TDC. If they are not, rotate the
crankshaft one complete turn.
Figure 6: Timing Mark
4. Measure the valve clearance for No. 1 cylinder, with a
feeler gauge.
Standard valve clearances for a cold engine are:
Intake (IN)........................0.0098 in. (0.25 mm)
Exhaust (EX)....................0.0098 in. (0.25 mm)
5. To adjust valve clearance, loosen the lock nut on the
adjustment screw. Insert a feeler gauge between the
rocker arm and the valve stem cap. Adjust, while
measuring the clearance, until the feeler gauge slides
with a slight drag. Tighten the lock nut and recheck
the clearance (Figure 7).
Figure 7: Valve Adjustment
6. Adjust the remaining valves turning the engine 1800
in the cylinder order of 1-3-4-2.
7. Replace the rocker arm cover.

OL944D 11/13
17
FUELS - GENERAL
1. Use only clean, high quality fuels of the following
specications, as dened by ASTM designation
D975 for diesel fuels:
a. Use grade No. 2 diesel at ambient temperatures
above freezing 32° F (0° C).
b. Use grade No. 1 at ambient temperatures below
freezing.
c. International fuel specications:
JIS K2204
ISO-8217-DMA
BS 2869 Part 1 Class A1
BS 2869 Part 2 Class A2
2. Use fuel having less that .2% sulphur of weight (less
than 0.05% recommended).
3. The cetane number should be 45 or higher.
4. Particulate contaminate should be 5.0 mg/l (0.00018
oz/U.S. gal) or lower.
5. DO NOT use these unsuitable grades of fuel:
a. Domestic heating oils, all types.
b. Class B engine.
c. Class D domestic fuels.
d. Class E, F, G or H industrial or marine fuels.
e. ASTM-D975-60T No. 4-D and higher number
fuels.
6. Storing fuel:
a. Keep dirt, scale, water, and other foreign matter
out of fuel.
b. Avoid storing fuel for long periods of time.
c. Fill the fuel tank at the end of each day’s
operation. This will reduce condensation.
SP8-10. FUEL FILTER
1. Your Lugger engine has a fuel lter installed. We
recommend the Northern Lights brand of fuel lters.
a. Check the primary fuel lter daily as
recommended by the lter manufacturer.
b. Change the lter as often as necessary or
every 250 hours.
c. Remove the fuel lter with a lter wrench.
d. Apply a coating of fuel to the o-ring of the new
fuel lter.
e. Tighten the new lter by hand, do not use a lter
wrench for tightening.
f. The lter should be dry.
g. Do not add fuel to the fuel lter before
installation, as this could cause unltered fuel to
enter the fuel pump.
h. Bleed the air out of the lter.
The fuel lter part number is:
L944D.........................24-51201
Servicing

18
OL944D 11/13
SP11. BLEEDING THE FUEL SYSTEM
CAUTION: Escaping diesel fuel under pressure
can penetrate skin causing serious personal injury.
Before disconnecting lines be sure to relieve all
pressure. Before applying pressure, be sure all
connections are tight and lines, pipes and hoses
aren't damaged. Fuel escaping from a very small
hole can be almost invisible. Use a piece of card-
board or wood, rather than hands, to search for
suspected leaks. If injured by escaping fuel, see a
doctor at once. Serious infection or reaction can
develop if proper medical treatment is not
administered immediately.
1. Fuel system air bleeding may be needed when:
a. After fuel has been added to a newly installed
engine.
b. A new fuel lter is installed.
c. The engine has run out of fuel.
d. The fuel lines, injection pump, or any other fuel
system component has been removed and
installed.
2. After changing the fuel lter, air only needs to be bled
from the fuel lter. To do this:
a. Loosen the air vent plug (#1 on Figure 8) on the fuel
lter by about 1-1/2 turns. (Be sure to cover the
vent with a cloth to prevent fuel from splashing.)
b. Turn the priming pump cap on the fuel feed pump
counterclockwise to unlatch it. Move the priming
pump plunger (#2 on Figure 8) up and down. To
close the pump turn the cap clockwise while
depressing it.
c. Close the air vent plug when no more air bubbles
can be seen in the fuel owing from the air vent
plug hole.
Servicing
Figure 8 Fuel Feed Pump
3. To bleed air at the fuel injection pump:
a. Turn the air vent plug (#3 on Figure 8) about 1-1/2
turns to loosen it. (Cover the vent with a cloth to
prevent fuel from splashing.)
b. Pump the feed pump cap up and down.
c. When there are no air bubbles to be seen in the
fuel owing from the air vent plug hole, push
down the priming pump cap and turn it clockwise
to lock it in place.
NOTE:
Do not close the air vent plug before locking the
priming pump cap in place, because the internal
pressure in the pump will prevent the priming
pump cap from returning to the original
position.
4. If the engine does not start after this bleeding
process, loosen a fuel line at the injector while
cranking the engine with the starter motor until
pure fuel escapes. Then tighten the connections.
Do each line one-at-a-time. After the engine has
started, use a piece of cardboard to look for fuel
leaks.

OL944D 11/13
19
Servicing
SP12. INJECTOR SERVICE
1. Injectors should be checked every 500 hours. This
check should be made by a Northern Lights dealer
or local injection repair station.
CAUTION: Escaping diesel fuel under pressure
can have sufcient force to penetrate the skin
causing serious personal injury. If injured by
escaping fuel, see a doctor at once.
2. Injector removal:
a. Clean loose dirt from around the injectors and
the fuel lines.
b. Relieve high pressure in the fuel lines by
loosening the delivery line are nuts at each
injector.
c. Remove delivery lines by disconnecting them
from the injectors and injection pump.
Remove all lines as an assembly; do not remove
the spacers. Cover the ends of the lines, the injector
inlets,and the injection pump outlets to keep dirt out.
d. Remove the return line retaining bolts, washers,
and return line.
e. Loosen the injector retaining nuts at the same
time a little at a time. Remove the injector.
f. Remove the injector seat. Cover the holes to
prevent debris from entering the cylinders.
Note: Do not use pry bars to remove injectors
from the cylinder head.
3. Injector repair and cleaning:
a. Take injectors to your Northern Lights dealer
or local injection repair station for testing and
service.
4. Injector installation:
a. Install new injector seal washer seat and
injector. Evenly tighten the injector retaining
nuts to 39.1 to 47.7 ft/lbs (53.0 to 64.7 N•m), or
5.4 to 6.6 kgf•m. Do not overtighten.
b. Reinstall the return line using new sealing
washers. Tighten bolts to 13.0 to 15.9 ft/lbs
(17.7 to 21.6 N•m), or 1.8 to 2.2 kgf•m.
NOTE: Overtightening can damage injectors.
c. Reinstall injection lines. Tighten
are nuts at injection pump to 19.5 to 23.9
ft/lbs (26.5 to 32.4 N•m), or 2.7 to 3.3 kgf•m.
Leave the lines loose at injectors for bleeding.
d. Bleed the injection lines. Crank the
engine to ll the lines. Tighten are nuts at
injectors to 15.2 to 18.1 ft/lbs (20.6 to 24.5 N•m),
2.1 to 2.5 kgf•m.
e. Start the engine and check for leaks using a
piece of paper or cardboard. Do not use your
hand to check for leaks.

20
OL944D 11/13
SP13. INJECTION PUMP
1. Since operating conditions may vary considerably,
it is difcult to give a denite interval for checking
the injection pump. But as a rule, pump settings,
maximum speed, idle speed and exhaust smoke
should be checked after every 2000 hours of
operation. Service of the fuel injection pump should
only be done if checks indicate pump malfunction.
2. Black smoke can be an indication of pump
malfunction. Before servicing the pump, check other
possible causes:
a. Check cleanliness of the air lter.
b. Check valve clearances.
c. Clean and check injectors.
3. Any repair which involves disassembly of the
injection pump must be carried out by specially
trained mechanics with the proper tools and test
equipment.
NOTE: All warranties on the engine become null
and void if the injection pump seals are
broken by unauthorized persons.
4. Injection Pump Removal:
CAUTION: Escaping diesel fuel under pressure
can have sufcient force to penetrate the skin,
causing serious personal injury. If injured by
escaping diesel fuel, see a doctor at once.
a. Clean the injection pump, hoses, and area
around the pump with a cleaning solvent or steam
cleaner.
NOTE: Never steam clean or pour cold water
on an injection pump while the engine is
running or the pump is warm.
b. Remove the injection lines from the
pump and injectors. Remove all lines as an
assembly. Do not remove the spacers. Cover the
ends of the lines, the injector inlets, and the
injection pump outlets to keep dirt out of the
injectors, lines, and pump.
c. Align timing marks on timing gear by engaging
Servicing
5. Injection Pump Installation:
a. Install the fuel injection pump after having
aligned its gear alignment mark with that of
the idler gear alignment mark as shown in
Figure 9 above. When the alignment marks
of the timing gears align as in the diagram
above, the No. 1 piston is top dead center in
the compression stroke.
b. Install the injection pump to the side of the
engine rst then put in the end bolts, and
then the tube with its bolts, and then the side
bracket.
c. Torque mounting bolts to 13.0 - 18.1 ft/lbs
(17.7 to 24.5 N•m), 1.8 to 2.5 kgf•m.
Figure 9: Timing Marks
c. (cont.)
the turning socket (part #5830973100) with the
crankshaft pulley nut and turn it clockwise (when
viewed at the front of the engine). Stop where
the “O” mark on the outside of the crankshaft
pulley is aligned with the pointer on the timing
gear case. To check Top Dead Center of the No.
1 cylinder, move the rocker arms of the inlet and
exhaust valves up and down, checking that the push
rods do not push up the rocker arms of the valves.
This is Top Dead Center of the No. 1 piston. If
the pushrods do push up the rocker arms, rotate
the crankshaft one more turn.
d. Remove the pump support bracket on rear of
pump.
e. Remove the 4 mounting nuts.
f. Take the pump to your Northern Lights dealer or
an injection pump repair station for testing and
service.