Generac Power Systems 53187 - Manual (Page 104)

PART 4
ENGINE FUEL SYSTEM
1
SECTION 4.5
FUEL NOZZLES AND HOLDERS
Section 4.5
FUEL NOZZLES AND HOLDERS
General
Fuel, supplied by the injector pump, is delivered to
the nozzle holder and to the nozzle body. When fuel
pressure is sufficient to compress the spring, fuel is
sprayed from the nozzle and into the combustion cham­
ber.
Specifications
Needle Valve Diameter....................0.236 inch (6mm)
Pintle Diameter................................ 0.039 inch (1mm)
Valve Opening Pressure.................. 1636-1778 psi
Adjusting Pressure...........................1778-1849 psi
Spraying Angle................................ 12*
Check Injection Pressure
Use a nozzle tester to check injection pressure. Ad­
just the pressure at which fuel injection occurs by
using shims, so that injection begins at 1707 psi (120
kg/cm^).
NOTE: Injection pressure Increases or decreases
about 142.23 psi (10 kg/cnr) for a shim 0.1m m
(0.004 Inch) thick.
Using the nozzle tester, check the spray pattern as
follows:
□ There should be no fuel droplets in the spray.
□ The spray pattern should be a conical shape with
respect to the nozzle axis.
□ When sprayed at a distance of 11 -12 inches (30cm)
from a sheet of white paper, the spray pattern should
be a conical shape.
Use the nozzle tester to increase nozzle pressure to
1422 psi (100 kg/cm^). At that pressure there should
be no leakage from the bozzle tip.
PAGE 4.5-1