OM673L3 5/21
2
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 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.
Introduction
Serial Numbers
s
MODELS INCLUDED
This manual covers the operating instructions for:
M673L3, M673L3G, M673LD3 and M673LD3G
marine generator sets.
Model Numbers
Model numbers give the unit's application, block model, aspiration, and RPM:
Unit Identification
Your set has three serial numbers:
1
an engine number stamped
on the block,
2
a generator plate, and
3
a generator set plate.
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 in
Figure 1
.
Note, an additional label with the set serial number is placed on the
upper front corner of the generator junction box.
Updated 8-6-19
L, D, G, 3
M -
Northern Lights marine
generator set
Model number of engine block
Bore Cylinders
67
mm
3
L
- Long stroke
D
- Series designation
G
- GEM series base frame
3
- US EPA Tier III compliant
+
+
M
673
Northern Lights marine diesel generator set with a 673 engine long stroke, TF-276D generator end, US EPA Tier III, 6 kW.
M
673L3
=
Northern Lights marine diesel generator set with a 673 engine long stroke, TF-276D generator end, GEM series base frame,
US EPA Tier III, 6 kW.
M
673L3G
=
Northern Lights marine diesel generator set with a 673 engine long stroke, TF-276D generator end, GEM series base
frame, US EPA Tier III, 5 kW.
M
673LD3G
=
Northern Lights marine diesel generator set with a 673 engine long stroke, TF-276D generator end US EPA Tier III, 5 kW.
M
673LD3
=
