Fast Idle; Fast Idle Adjustment - Suzuki GSX-R750 Service Manual

5-24 FUEL SYSTEM AND THROTTLE BODY

FAST IDLE

The fast idle system is automatic type.
When the fast idle cam is turned by the secondary throttle valve
actuator, the cam pushes the lever on the throttle valve shaft
causing the throttle valve to open and raise the engine speed.
When the engine has warmed up, depending on the water tem-
perature, ambient temperature and lapsed time, the fast idle is
cancelled allowing the engine to resume idle speed.
Ambient Temp.
–5 °C (23 °F) 1 500 – 2 000 r/min
15 °C (59 °F) 1 500 – 2 000 r/min
25 °C (77 °F) 1 500 – 2 000 r/min

FAST IDLE ADJUSTMENT

• Lift and support the fuel tank. (5-3)
• Start up the engine and run it in idling condition for warming
up at the water temperature of 80 – 90 °C (176 – 194 °F).
• Set the idle rpm to 1 200 r/min by the throttle stop screw 1.
• Check and adjust the TP sensor. (4-20)
• Turn the ignition switch OFF.
• Disconnect the TP sensor coupler and install the test harness.
• Start up the engine.
• Measure the TP sensor output voltage at the wire terminals
(between + terminal Red and - terminal Black).
 TP sensor output voltage at idle position: Approx. 1.125 V
 09900-28630: TPS test wire harness
09900-25008: Multi-circuit tester set
 Tester knob indication: Voltage ()
• Turn the ignition switch OFF.
• Remove the air cleaner box (5-14) and disconnect the
STVA coupler. (5-15)
• Turn the ignition switch ON.
• Open the secondary throttle valve fully by turning it with your
finger.
• With the secondary throttle valve held at this position, mea-
sure the output voltage of the TP sensor as shown.
Fast idle cancel-
Fast idle rpm
Approx. 100 sec.
Approx. 20 sec.
Approx. 15 sec.
ling time
V