Yanmar 4LHA-HTP Operation Manual page 468

Chapter 3 Fuel Injection Equipment
7. Fuel Injection Nozzle
(3) Inspecting the stopper
Check for scratches/wear in seals on both ends,
check for abnormal w e a r on the surface where it
comes in contact with t h e nozzle; replace if the
stop plate is excessively w o r n .
Hole type
Nozzle contact surface \
Seal surface
Nozzle contact surface w e a r limit
(4) Inspecting the nozzle spring
Replace the nozzle spring if it is extremely bent,
or if the surface is scratched or rusted.
(5) Nozzle holder
Check the oil seal surface for scratches/wear-
replace if wear is excessive.
6-5 Fuel injection nozzle reassembly
The fuel injection nozzle is reassembled in the opposite
order to disassembly.
(1) Insert the adjusting shims, nozzle spring and nozzle
spring seat in the nozzle holder, mount the stop
plate with the pin, insert the nozzle body/nozzle
set and tighten the nut.
(2) Use the special holder when tightening the nut for
the hole type nozzle, as in disassembly.
N o z z l e nut tightening torque
Hole type nozzle
f l Pin
mm (in.)
0.1 (0.0039)
N l k g O - m
39 2 - 44.1(4-4.5)
7-6 A d j u s t i n g fuel injection n o z z l e
7-6.1 Adjusting opening pressure
Mount the fuel injection nozzle on the nozzle tester
and use the handle to measure injection starting pres-
sure. If it is not at the specified pressure, use the adjust-
ing shims to increase/decrease pressure.
Hole type
Injection starting pressure
4LHA-STE/STZE/STP/STZP
26.5—27.5 (270-280)
3-2-46
i4LHA Series
MPa(kgf/cm
4LHA-DTE/DTZE/DTP/DTZP
23.5-24.5 (240-250)
)
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