Yamaha Wr250r 2008 Manual
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THROTTLE BODIES 7-6 EAS26980 CHECKING THE INJECTORS WARNING EWA32D1009 Replace the fuel injector with a new one if you have dropped or impacted it. 1. Check: Injectors Damage → Replace. EAS26990 CHECKING THE THROTTLE BODIES 1. Check: Throttle bodies Cracks/damage → Replace the throttle bod- ies as a set. 2. Check: Fuel passages Obstructions → Clean. a. Wash the throttle bodies in a petroleum- based solvent. Do not use any caustic carburetor cleaning solution. b. Blow out all of the passages with com- pressed air. EAS27000 CHECKING THE PRESSURE REGULATOR WARNING EWA32D1010 Replace the pressure regulator with a new one if you have dropped or impacted it. 1. Check: Pressure regulator Damage → Replace. EAS27010 CHECKING THE PRESSURE REGULATOR OPERATION 1. Check: Pressure regulator operation a. Remove the fuel tank. Refer to “FUEL TANK” on page 7-1. b. Connect the pressure gauge “1” and adapter “2” to the fuel injection pipe. c. Install the fuel tank. Refer to “FUEL TANK” on page 7-1. d. Start the engine. e. Measure the fuel pressure. f. Use the vacuum/pressure pump gauge set to adjust the fuel pressure in relation to the vac- uum pressure as described below. NOTE: The vacuum pressure should not exceed 100 kPa (14.2 psi) (1.00 kg/cm 2 ). Faulty → Replace the pressure regulator. Vacuum/pressure pump gauge set 90890-06756 Mityvac brake bleeding tool YS-42423 Pressure gauge 90890-03153 YU-03153 Fuel pressure adapter 90890-03176 YM-03176 Fuel pressure 250 kPa (35.6 psi) (2.50 kg/cm 2 ) Increase the vacuum pressure → Fuel pressure is decreased Decrease the vacuum pressure → Fuel pressure is increased 1 2
THROTTLE BODIES 7-7 EAS27030 ADJUSTING THE THROTTLE POSITION SENSOR WARNING EWA32D1011 Replace the throttle position sensor with a new one if you have dropped or impacted it. NOTE: Before adjusting the throttle position sensor, the engine idling speed should be properly adjusted. 1. Check: Throttle position sensor Refer to “CHECKING THE THROTTLE PO- SITION SENSOR” on page 8-79. 2. Adjust: Throttle position sensor angle a. Connect the throttle position sensor coupler to the wire harness. b. Connect the digital circuit tester to the throttle position sensor. c. Measure the throttle position sensor voltage. d. Adjust the throttle position sensor angle so that the voltage is within the specified range. e. After adjusting the throttle position sensor an-gle, tighten the throttle position sensor screws. Positive tester probe Blue “ 1 ” Negative tester probe Black/Blue “ 2 ” Digital circuit tester 90890-03174 Model 88 Multimeter with tachom- eter YU-A1927 Throttle position sensor Output voltage (when the engine is idling) 0.63 – 0.73 V L Y B/L 12
AIR INDUCTION SYSTEM 7-9 EAS27040 AIR INDUCTION SYSTEM 2 1 3 4
AIR INDUCTION SYSTEM 7-10 1. Air filter case 2. Air induction system hose 3. Air cut-off valve 4. Air induction system pipe
AIR INDUCTION SYSTEM 7-11 Removing the air cut-off valve assembly Order Job/Parts to remove Q’ty Remarks Seat Refer to“GENERAL CHASSIS” on page 4-1. Side cover (left/right) Air scoop (left/right) Fuel tank Refer to“FUEL TANK” on page 7-1. 1 Air induction coupler 1 Disconnect. 2 Air induction system pipe 1 3 Gasket 1 4 Pipe3 1 5 Air induction system hose 1 6 Air cut-off valve assembly 1 For installation, reverse the removal proce- dure. 1 2 3 4 5 6 T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
AIR INDUCTION SYSTEM 7-12 EAS27060 CHECKING THE AIR INDUCTION SYSTEM Air induction The air induction system burns unburned ex- haust gases by injecting fresh air (secondary air) into the exhaust port, reducing the emission of hydrocarbons. When there is negative pressure at the exhaust port, the reed valve opens, allow- ing secondary air to flow into the exhaust port. The required temperature for burning the un- burned exhaust gases is approximately 600 to 700 ° C. Air cut-off valve The air cut-off valve is controlled by the signals from the ECU in accordance with the combus- tion conditions. Ordinarily, the air cut-off valve opens to allow the air to flow during idle and closes to cut-off the flow when the vehicle is be- ing driven. 1. Check: Hoses Loose connections → Connect properly. Cracks/damage → Replace. Pipes Cracks/damage → Replace. 2. Check: Reed valve Reed valve stopper Reed valve seat Cracks/damage → Replace the reed valve.3. Check: Air cut-off valve Cracks/damage → Replace. A. From the air filter B. To the cylinder head A B
AIR INDUCTION SYSTEM 7-13 EAS32D12011 CANISTER (FOR CALIFORNIA) Removing the canister Order Job/Parts to remove Q’ty Remarks 1 Canister cover 1 2 Canister 1 3 Hose (fuel tank – roll over valve) 1 4 Roll over valve 1 5 Hose (roll over valve – canister) 1 6 Hose (canister – throttle body) 1 For installation, reverse the removal proce- dure. T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) 1 T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) 2 56 3 4
1 2 3 4 5 6 7 8 9 ELECTRICAL SYSTEM IGNITION SYSTEM ........................................................................................8-1 CIRCUIT DIAGRAM .................................................................................8-1 TROUBLESHOOTING .............................................................................8-3 ELECTRIC STARTING SYSTEM...................................................................8-5 CIRCUIT DIAGRAM .................................................................................8-5 STARTING CIRCUIT CUT-OFF SYSTEM OPERATION .........................8-7 TROUBLESHOOTING .............................................................................8-9 CHARGING SYSTEM ....................................................................................8-11 CIRCUIT DIAGRAM .................................................................................8-11 TROUBLESHOOTING .............................................................................8-13 LIGHTING SYSTEM .......................................................................................8-15 CIRCUIT DIAGRAM .................................................................................8-15 TROUBLESHOOTING .............................................................................8-17 SIGNALING SYSTEM ....................................................................................8-19 CIRCUIT DIAGRAM .................................................................................8-19 TROUBLESHOOTING .............................................................................8-21 COOLING SYSTEM .......................................................................................8-25 CIRCUIT DIAGRAM .................................................................................8-25 TROUBLESHOOTING .............................................................................8-27 FUEL INJECTION SYSTEM ..........................................................................8-29 CIRCUIT DIAGRAM .................................................................................8-29 ECU SELF-DIAGNOSTIC FUNCTION.....................................................8-31 FAIL-SAFE ACTIONS (SUBSTITUTE CHARACTERISTICS OPERATION CONTROL) ......................................................................8-32 TROUBLESHOOTING METHOD.............................................................8-34 DIAGNOSTIC MODE ...............................................................................8-34 TROUBLESHOOTING DETAILS .............................................................8-41 FUEL PUMP SYSTEM ...................................................................................8-55 CIRCUIT DIAGRAM .................................................................................8-55 TROUBLE SHOOTING ............................................................................8-57 ELECTRICAL COMPONENTS ......................................................................8-59 CHECKING THE SWITCHES ..................................................................8-63 CHECKING THE BULBS AND BULB SOCKETS ....................................8-66 CHECKING THE FUSES .........................................................................8-67 CHECKING AND CHARGING THE BATTERY........................................8-68 CHECKING THE RELAYS .......................................................................8-71 CHECKING THE DIODE ..........................................................................8-73 CHECKING THE IGNITION SPARK GAP ...............................................8-74 CHECKING THE IGNITION COIL ............................................................8-74
CHECKING THE CRANKSHAFT POSITION SENSOR ..........................8-75 CHECKING THE LEAN ANGLE SENSOR ..............................................8-75 CHECKING THE STATOR COIL .............................................................8-76 CHECKING THE RECTIFIER/REGULATOR ...........................................8-76 CHECKING THE HORN...........................................................................8-77 CHECKING THE SPEED SENSOR .........................................................8-77 CHECKING THE FUEL SENDER (FUEL PUMP) ....................................8-78 CHECKING THE COOLANT TEMPERATURE SENSOR .......................8-78 CHECKING THE RADIATOR FAN MOTOR ............................................8-79 CHECKING THE THROTTLE POSITION SENSOR ................................8-79 CHECKING THE EXUP SERVO MOTOR ...............................................8-80 CHECKING THE INTAKE AIR PRESSURE SENSOR ............................8-80 CHECKING THE INTAKE AIR TEMPERATURE SENSOR .....................8-80 CHECKING THE INTAKE SOLENOID.....................................................8-81