Yamaha YZ250F(X), Owner'S Service Manual

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4-43
OIL PUMP
CHECKING THE OIL PUMP
1. Inspect:
• Oil pump drive gear "1"
• Oil pump drive shaft "2"
• Rotor housing "3"
• Oil pump cover "4"
Cracks/wear/damage
→
Replace.
2. Measure:
• Tip clearance "a"
(between the inner rotor "1" and
outer rotor "2")
• Side clearance "b"
(between the outer rotor "2" and
rotor housing "3")
• Housing and rotor clearance "c"
(between the rotor housing "3"
and rotors "1" "2")
Out of specification
→
Replace
the oil pump assembly.
3. Check:
• Unsmooth
→
Repeat steps #1 and
#2 or replace the defective parts.
INSTALLING THE OIL PUMP
1. Install:
• Oil pump drive shaft "1"
• Washer "2"
• Dowel pin "3"
• Inner rotor 1 "4"
• Apply the engine oil on the oil pump
drive shaft and inner rotor 1.
• Fit the dowel pin into the groove in
the inner rotor 1.
2. Install:
• Outer rotor 1 "1"
Apply the engine oil on the outer rotor
1.
3. Install:
• Oil pump cover "1"
• Screw (oil pump cover) "2"
• Dowel pin "3"
• Inner rotor 2 "4"
• Circlip "5"
• Apply the engine oil on the inner ro-
tor 2.
• Fit the dowel pin into the groove in
the inner rotor 2.
4. Install:
• Outer rotor 2 "1"
• Dowel pin "2"
• Oil pump assembly "3"
• Bolt (oil pump assembly)
[L = 25 mm (0.94 in)] "4"
• Bolt (oil pump assembly)
[L = 30 mm (1.18 in)] "5"
Apply the engine oil on the outer rotor
2.
5. Install:
• Oil pump drive gear "1"
• Washer "2"
• Circlip "3"
Apply the engine oil on the oil pump
drive gear inner circumference.
Tip clearance "a":
0.12 mm or less (0.0047
in or less)
<Limit>: 0.20 mm
(0.008 in)
Side clearance "b":
0.09–0.17 mm (0.0035–
0.0067 in)
<Limit>: 0.24 mm
(0.009 in)
Housing and rotor clear-
ance "c":
0.03–0.10 mm (0.0012–
0.0039 in)
<Limit>: 0.17 mm
(0.0067 in)
Screw (oil pump cover):
2 Nm (0.2 m•kg, 1.4
ft•lb)
Bolt (oil pump assem-
bly):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Bolt (oil pump assem-
bly):
10 Nm (1.0 m•kg, 7.2
ft•lb)