Introduction; Models Included; Model Numbers; Serial Numbers - Northern Lights OM844W3 Operator's Manual

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.

MODELS INCLUDED

This manual covers the operating instructions for:
M844 marine generator sets,
W3
M844 marine generator sets,
DW3
M844 marine generator sets, and
LW3
M20
commercial generator sets.
CRW3
Fill in the model number of your unit in the blank space provided.
This will give you a reference whenever service or maintenance is required:
Model numbers give the unit's application, block model, aspiration, and RPM:
M
M - Northern Lights marine generator set
=
M844W Northern Lights marine diesel generator set with
3
an 844 engine and a PX-316K2 generator end.
M844DW Northern Lights 16 kW marine diesel generator set
=
3
with an 844L engine and a PX-320K2 generator end.
Generator set serial number plate.
Revised 11/8/13

Introduction

Failures can begin with minor problems that are
overlooked and become amplified 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.
Unit Identification
NOTE: There are two versions of the 844W3 engine.
The standard engine is designated 844W3. The long-
stroke engine is designated 844LW3. You will need to
know which engine you have to use this manual and to
order parts.

Model Numbers

844
Model number of engine block
+
Bore Cylinders
84 mm 4
M844LW
3
M20CRW3

Serial Numbers

Your set has three serial numbers:
on the block, a generator plate, and
2
Use the serial number on the generator set plate when ordering parts
or in correspondence. The generator set plate is found on the service
side of the generator and resembles the drawing at left.
OM844W3 11/13
2
My Northern Lights generator set MODEL number is:
W, D, L, C, 3
W - New winding
+
D - Series Designation
L - Long stroke version
C - Commercial version
3 - Tier 3
= Northern Lights marine diesel generator set with
an 844L engine and a PX-320K2 generator end.
=
Northern Lights 20 kW (@ 60 Hz) commercial grade
marine generator set with a special generator end.
an engine number stamped
1
a generator set plate.
3