Generac Power Systems 53187 - Manual (Page 96)

PART 4
ENGINE FUEL SYSTEM
i
SECTION 4.1- INTRODUCTION TO
THE DIESEL FUEL SYSTEM
Section 4.1
INTRODUCTION TO THE DIESEL FUEL SYSTEM
General
The diesel engine does not require an electrical
ignition system. The diesel fuel is ignited by heat which
is created by extremely high pressures In the combus­
tion chambers during the compression stroke. The
compression ratio of the engine is 23 to 1, to provide à
cylinder compression pressure of nearly 340 psi.
Fuel Recommendations
Diesel fuels are less volatile than gasoline and
gaseous fuels. For that reason, diesel fuel is consid­
ered safer than the more volatile fuels. Because diesel
fuels are safer, careless practices often result which
can lead to serious problems with engine performance
and reliability.
RECOMMENDED FUEL:
Use clean, fresh. No. 2D diesel fuel having a Ce­
tane number of at least “40". Where the vehicle is
equipped with a diesel engine, the vehicle fuel tank may
also supply fuel to the NP series generator.
KEEP DIESEL FUEL CLEAN:
Dirt or water in the fuel system is a major cause of
engine, injection pump or injection nozzle failure. Fuel
must be kept clean and free of moisture.
DO NOT ALTER THE INSTALLATION:
When installed, the fuel system was in full compli­
ance with applicable codes, standards and regulations.
Do NOT make any changes that might render the
system unsafe or in non-compliance with such codes,
standards and regulations.
CHECK FOR LEAKS PERIODICALLY:
Fuel lines and fittings must be kept tight and must
be maintained free of leaks. An improperly tightened
fuel line might show no evidence of leakage, but may
permit air to enter the fuel system. Air In the system will
cause hard starting and rought operation.
NOTE: The diesel engine Is self-bleeding and
should never require hand prim ing or bleeding of
air from the system .
Fuel System Components
See Figure 1, below. During operation, fuel is
pumped from the fuel tank, to a 12 volts DC electric fuel
pump, through a fuel filter, a fuel injector pump, fuel
injectors, and into the engine combustion chambers.
The following facts apply to the various fuel system
components:
INJECTORS
Figure 1. Engine Fuel System (Typical)
PAGE 4.1-1