Adjusting No. 1 Opening Pressure; Fuel Injection Nozzle Installation - Yanmar 6LPA-STP2 Service Manual

Fuel Injection Nozzle
12/05

Adjusting No. 1 Opening Pressure

1. Reassemble the fuel injection nozzle assembly
to the operating condition as shown in
(Figure 6-17).
• Align the holes of the nozzle holder body, tip
packing and nozzle holder body.
• If the adjusting shim thickness originally used
is unknown, use a shim 1.5 mm (0.06 in.)
thickness.
2. Install the assembly to the tester, pressurize
and read the pressure gauge when the injection
pressure begins to decrease. CAUTION!
ALWAYS wear eye protection when
servicing the engine.
• No. 1 opening pressure: 250 to 260 kgf/cm
24.52 to 25.50 MPa (3556 to 3698 psi)
• Determine if the nozzle operates normally or
not by listening to the swishing sound. If the
valve opening pressure is out of the specified
range, disassemble the nozzle and select an
appropriate adjusting shim to replace the shim
at the upper portion of No. 1 pressure spring
from the appropriate chart below.
Adjusting Shim Thickness
0.825 mm 0.900 mm
(0.032 in.) (0.035 in.)
1.050 mm 1.125 mm
(0.041 in.) (0.044 in.)
1.275 mm 1.350 mm
(0.050 in.) (0.0531 in.)
1.500 mm 1.575 mm
(0.059 in.) (0.062 in.)
1.725 mm 1.800 mm
(0.0679 in.) (0.0708 in.)
1.950 mm 2.000 mm
(0.0767 in.) (0.0787 in.)
2.175 mm
(0.0856 in.)
Note: Changing the adjusting shim thickness
by 0.025 mm changes the valve opening
pressure by approximately 3.8 kgf/cm
0.37 MPa (54 psi).
6LPA Service Manual
2
0.975 mm
(0.038 in.)
1.200 mm
(0.047 in.)
1.425 mm
(0.0561 in.)
1.650 mm
(0.0649 in.)
1.875 mm
(0.0738 in.)
2.100 mm
(0.0826 in.)
- -
2
,
© 2007 Yanmar Marine International
• Change only one adjusting shim at the upper
portion of No. 1 pressure spring.
3. After the injection test, check for leakage from
from the injection hole. There should be no
leakage.

Fuel Injection Nozzle Installation

1. Install a new O-ring onto the fuel injection
nozzle.
2. Insert a new nozzle seat in the hole in the fuel
injection nozzle of the cylinder head.
3. Install the fuel injection nozzle to the cylinder
head, using the nozzle holder clamp, washer
and bolt (Figure 6-42). Torque to: 255 kgf·cm,
25.01 N·m (18.4 lb-ft)
,
Figure 6-42
4. Install a new nozzle holder seal to the cylinder
head (Figure 6-43).
Figure 6-43
FUEL SYSTEM
Figure 6-42
Figure 6-43
0005305
0005306
6-25