Honda Crf250l Service Manual

							7-16
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FUEL SYSTEM
Install a new O-ring [1] to the IACV [2].
Install the IACV by aligning its slide valve slot with the
pin in the throttle body.
Install the set plate [1] by aligning its slot with the IACV
tab, then tighten the torx screws [2] to the specified
torque.
Connect the IACV 4P (Black) connector [3].
Install the fuel tank (page 7-8).
INSPECTION
The IACV is installed on the throttle body and is
operated by the step motor.  When the ignition switch is
turned ON, the IACV oper ates for a few seconds. 
Check the step motor operating sound with the ignition
switch turned ON and engine stop switch  .
If the IACV does not sound with no MIL blinking, inspect
as follows:
Remove the IACV (page 7-15).
If the idling is unstable, check the condition of the O-
ring.
Temporarily connect the IACV 4P (Black) connector [1].
Turn the ignition switch ON and engine stop switch  
while holding the slide valve [2] as shown.
The slide valve should move back and forth.
Install the IACV (page 7-15).
[1]
[2]
Align
TORQUE: 2.1 N·m (0.2  kgf·m, 1.5 lbf·ft)
Align
[1]
[2][3]
[1]
[2] 
						

							7-17
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FUEL SYSTEM
SECONDARY AIR SUPPLY SYSTEM
SYSTEM INSPECTION
Start the engine and warm it up to coolant temperature
is 80°C (176°F).
Stop the engine.
Remove the PAIR check valve (page 7-18).
Check that the reed valve [1]  is clean and free of carbon
deposits.
If the reed valve is carbon fouled, inspect the following:
– Reed valve for deterioration or damage
– Rubber seat [2] for crack, deterioration or damage
– Reed valve stopper [3] for damage or deformation
Replace the PAIR check valve if necessary.
Start the engine and open the  throttle slightly to be
certain that air is sucked in through the air supply hose.
If the air is not drawn in, check the air supply hoses [1]
for clogs. If the hoses are normal, inspect the PAIR
control solenoid valve [2] (page 7-17).
PAIR CONTROL SOLENOID VALVE
REMOVAL/INSTALLATION
Remove the right fuel tank shroud (page 2-4).
Disconnect the PAIR control solenoid valve 2P (Black)
connector [1].
[1]
[2]
[3]
FRESH AIR
EXHAUST GAS
[2]
[1]
[1] 
						

							7-18
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FUEL SYSTEM
Remove the bolts [1], collars [2] and PAIR control
solenoid valve [3] from the stay.
Disconnect the air supply hoses [4] from the PAIR
control solenoid valve.
Installation is in the reverse order of removal.
INSPECTION
Remove the PAIR control solenoid valve (page 7-17).
Check that air does not flow (A) to (B) when the 12 V
battery is connected to the PAIR control solenoid valve
terminals. Air should flow (A) to (B) when there is no
voltage applied to the PAIR control solenoid valve
terminals.
Measure the resistance between the connector
terminals.
If it is out of standard, replace the PAIR control solenoid
valve.
PAIR CHECK VALVE REMOVAL/
INSTALLATION
Remove the bolts [1] and  PAIR check valve cover [2].
[3][4]
[1]/[2]
(A)
(B)
STANDARD:  20 – 24 Ω (20°C/68°F)
[2]
[1] 
						

							7-19
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FUEL SYSTEM
Remove the PAIR check valve [1] and baffle plate [2]
from the cylinder head cover.
Installation is in the reverse order of removal.
TORQUE: PAIR check valve cover bolt:5.2 N·m (0.5 kgf·m, 3.8 lbf·ft)[2][1] 
						

							MEMO
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							8-1
8
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8. LUBRICATION SYSTEM
SERVICE INFORMATION ·····························8-2
TROUBLESHOOTING···································8-2
LUBRICATION SYSTEM DIAGRAM ············8-3ENGINE OIL STRAINER SCREEN ··············· 8-4
OIL PUMP ····················································· 8-4
PRESSURE RELIEF VALVE ··················\
······ 8-7 
						

							8-2
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LUBRICATION SYSTEM
LUBRICATION SYSTEMSERVICE INFORMATION
GENERAL
 • The oil pump can be serviced with the engine installed in the frame.
 • The service procedures in this section must be performed with the engine oil drained.
 • When removing and installing the oil pump, use care not to allow dust or dirt to enter the engine.
 • If any portion of the oil pump is worn beyond the spec ified service limits, replace the oil pump as an assembly.
 • After the oil pump has been installed,  check that there are no oil leaks.
TROUBLESHOOTING
Engine oil level too low, high oil consumption
 • Oil consumption
 • External oil leaks
 • Worn valve guide or stem seal
 • Worn piston rings
 • Improperly installed piston rings
 • Worn cylinder
Engine oil contamination
 • Oil not changed often enough
 • Worn valve guide or stem seal
 • Worn piston rings
 • Improperly installed piston rings
 • Worn cylinder
Oil emulsification
 • Faulty cylinder head gasket
 • Leaky coolant passage
 • Entry of water
 • Faulty water pump mechanical seal
Used engine oil may cause skin cancer if repeatedly left in co ntact with the skin for prolonged periods. Although this is unlikely 
unless you handle used oil on a daily basis, it is still advisable  to thoroughly wash your hands with soap and water as soon as  
possible after handling used oil. 
						

							8-3
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LUBRICATION SYSTEM
LUBRICATION SYSTEM DIAGRAM
PRESSURE RELIEF VALVE
OIL PUMP
CAMSHAFT
COUNTERSHAFT
ROCKER ARM
MAINSHAFT
CRANKSHAFT
OIL FILTER
OIL STRAINER SCREEN 
						

							8-4
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LUBRICATION SYSTEM
ENGINE OIL STRAINER SCREEN
REMOVAL/INSTALLATION
Remove the right crankcase cover (page 12-4).
Pull the oil strainer screen [1] out of the crankcase.
Wash the oil strainer screen thoroughly in
nonflammable or high flash point solvent until all
accumulated dirt has been removed.
Blow dry it with compressed air to clean completely.
Before installing the strainer, it should be examined
closely for damage, and make sure the sealing rubber
is in good condition.
Install the oil strainer screen  with the thin edge facing in
and flange side facing up as shown.
Install the right crankcase cover (page 12-8).
OIL PUMP
REMOVAL/DISASSEMBLY
Remove the right crankcase cover (page 12-4).
Remove the oil pump driven gear [1].
Remove the oil pump mounting bolts [1] and oil pump
assembly bolt [2].
Remove the oil pump cover assembly [3].
Be careful not to
damage the oil
strainer screen.
[1]
OIL STRAINER SCREEN DIRECTION:
CRANKCASE
[1]
[1]
[2][3] 
						

							8-5
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LUBRICATION SYSTEM
Remove the inner rotor assembly from the oil pump
cover [1] while holding oil pump shaft [2].
Remove the oil pump shaft and lock pin [3] from the
inner rotor [4].
Remove the outer rotor [5] and washer [6].
Remove the dowel pins [1] from the oil pump body [2].
Remove the oil pump body [1] by releasing it from the
cam chain guide hook [2] and pressure relief valve [3].
Remove the dowel pins [4] and O-ring [5].
INSPECTION
Inspect the following parts for damage, abnormal wear,
deformation or burning.
– Oil pump driven gear
– Oil pump shaft
– Lock pin
– Inner rotor
– Outer rotor
– Oil pump body
Measure the oil pump clearances according to
LUBRICATION SYSTEM SPECIFICATIONS (page 1-
5).
If any of the measurement is out of the service limit,
replace the oil pump as an assembly.
[5]
[3][1]
[4][2]
[6]
[1][2]
[1]
[3]
[2]
[5]
[4]