Disconnect the main throttle sensor connector and connect the setting adapter [A] between these connectors.

Special Tool - Throttle Sensor Setting Adapter: 57001 -1538
Main Throttle Sensor Output Voltage Connections to Adapter: Digital Meter (+) → R (sensor V/W) lead
Digital Meter (–) → BK (sensor BR/BK) lead
Install the following parts temporarily.
Throttle Body Assy (see Throttle Body Assy Installation in the Fuel System (DFI) chapter) 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)
Throttle Sensor Setting Adapter [A]
Idle Speed Standard: 1 100 ±50 r/min (rpm)

Output Voltage
Standard: DC 0.64
0.68 V at idle
throttle opening
DC 3.89
4.09 V at full throttle
opening (for
reference)
NOTE
Example: In the case of a input voltage of 4.75 V.
0.64 × 4.75 ÷ 5.00 = 0.61 V
0.68 × 4.75 ÷ 5.00 = 0.65 V
Thus, the valid range is 0.61
0.65 V
If the reading is out of the standard, replace the throttle body assy.
If the reading is within the standard, 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] ←→ Main Throttle Sensor Connector [B] V/W lead (ECU terminal 25) [C] BR/BK lead (ECU terminal 13) [D]
If the wiring is good, 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).
Main Throttle Sensor Circuit

1. ECU
2. Subthrottle Sensor
3. Main Throttle Sensor
Main Throttle Sensor Resistance InspectionSpecial Tools and Sealant
Compression Gauge, 20 kgf/cm²:
57001-221
Valve Spring Compressor Assembly:
57001-241
Valve Spring Compressor Adapter,
25:
57001-1019
Valve Seat Cutter, 45° - 27.5:
57001-1114
Valve Seat Cutter, 45° - 32:
57001-1115
Valve Seat Cutter, 32° - 28:
57001-1119
Valve Seat Cutter ...
Drive Chain Slack Adjustment
Remove the cotter pin [A], and loosen the rear axle nut
[B].
Loosen the both chain adjuster locknuts [C].
If the chain is too loose, turn out the left and right chain
adjusters [D] evenly.
If the chain is too tight, turn in the left and right chain
adjusters evenly, and kick the wheel f ...
Piston Ring End Gap Inspection
Place the piston ring [A] inside the cylinder (upper
crankcase), using the piston to locate the ring squarely
in place. Set it close to the bottom of the cylinder, where
cylinder wear is low.
Measure the gap [B] between the ends of the ring with a
thickness gauge.
Piston Ring End Gap ...