Oxygen Sensor Removal/Installation
Refer to the Oxygen Sensor Removal/Installation (Equipped Models) in the Electrical System chapter.
Oxygen Sensor Inspection

Main Harness [B] Oxygen Sensor [C]
Special Tool - Measuring Adapter: 57001-1700

Oxygen Sensor Output Voltage Connections to Adapter: Digital Meter (+) → R (sensor BK) lead Digital Meter (–) → BK (sensor GY) lead

Do not disconnect the air switching valve connector [B].

Air Cleaner Housing (see Air Cleaner Housing Installation in the Fuel System (DFI) chapter) Fuel Tank (see Fuel Tank Installation in the Fuel System (DFI) chapter)

Measuring Adapter [A]
Output Voltage (with Plugs, Rich) Standard: DC 0.8 V or more

| WARNING The engine gets extremely hot during normal operation and can cause serious burns. Never touch a hot engine. |

Air Cleaner Housing (see Air Cleaner Housing Installation in the Fuel System (DFI) chapter) Fuel Tank (see Fuel Tank Installation in the Fuel System (DFI) chapter)
Output Voltage (without Plugs, Lean) Standard: DC 0.24 V or less
If the reading is out of the standard (with plugs: 0.8 V or more, without plugs: 0.24 V or less), remove the ECU and check the wiring for continuity between harness connectors.
Special Tool - Hand Tester: 57001-1394

Disconnect the ECU and sensor connectors.
Wiring Continuity Inspection ECU Connector [A] ←→ Oxygen Sensor Connector [B] W/BL lead (ECU terminal 35) [C] BR/BK lead (ECU terminal 13) [D]
If the wiring is good, replace the sensor.
If the reading is within the standard (with plugs: 0.8 V or more, without plugs: 0.24 V or less), check the ECU for its ground and power supply (see ECU Power Supply Inspection in the Fuel System (DFI) chapter).
If the ground and power supply are good, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
Oxygen Sensor Circuit

1. ECU
2. Oxygen Sensor
3. Ignition Switch
4. Joint Connector F
5. Joint Connector A
6. Fuse Box 1
7. Ignition Fuse 15 A
8. Relay Box
9. ECU Main Relay
10. Frame Ground 3
11. Starter Relay
12. ECU Fuse 15 A
13. Main Fuse 30 A
14. Battery
15. Engine Ground
Subthrottle Sensor Resistance Inspection
Exhaust Butterfly Valve Actuator Sensor (Service Code 34)Front Wheel Rotation Sensor Removal
NOTICE
The wheel rotation sensor should be handled carefully,
never struck sharply, as with a hammer, or allowed
to fall on a hard surface since the wheel rotation
sensor is precision made. Be careful not to get
water or mud on the wheel rotation sensor.
Do not try to disassemble or repair t ...
Exhaust Butterfly Valve Cable Removal
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Open the clamp [A] and free the cables.
Slide the dust covers [B].
Loosen the locknuts [A], and turn the adjusters [B] to give
the cable plenty of play.
Remove the clamp [A].
Remove the up ...
Piston Ring Groove Width Inspection
Measure the piston ring groove width.
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
Standard:
Top [A] 0.82 0.84 mm (0.0323
0.0331 in.)
Second [B] 0.82 0.84 mm
(0.0323 0.0331 in.)
Service Limit:
0.92 mm (0.036 in.)
Second 0.92 mm (0.036 in.)
...