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 InspectionClutch
Clutch Operation Inspection
Pull the clutch lever just enough to take up the free play
[A].
Measure the gap between the lever and the lever holder.
If the gap is too wide, the clutch may not release fully. If
the gap is too narrow, the clutch may not engage fully. In
either case, adjust ...
Fuel Flow Rate Inspection
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions, creating the
potential for serious burns. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light. Do not smoke. T ...
Piston Ring, Piston Ring Groove Wear Inspection
Check for uneven groove wear by inspecting the ring seating.
The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.
With the piston rings in their grooves, make several measurements
with a thickness gauge [A] to determine pisto ...