Installation Instructions
4. Fuel System 
4-10 
Adjustment of Idle Speed 
 Caution 
y Air screw was set at factory, so no adjustment 
is needed. Note the number of turns it takes to 
screw it all the way in for ease of installation. 
y The parking brake must be used to stop the 
scooter to perform the adjustments. 
Use a tachometer when adjusting engine RPM. 
Screw in air adjustment screw gently, then back up 
to standard turns. 
Standard turns: 2±1/2 turns 
Warm up engine; adjust the throttle stopper screw 
of throttle valve to standard RPM. 
Idle speed rpm: 1500±100 rpm 
Connect the hose of exhaust analyzer to exhaust 
front end. Press test key on the analyzer. 
Adjust the pilot screw and read CO reading on the 
analyzer 
CO standard value: 1.3~2.0 % 
Accelerate in gradual increments; make sure rpm 
and CO value are in standard value after engine 
running in stable. If rpm and CO value fluctuated, 
repeat the procedures described above for 
adjusting to standard value. 
To this chapter contents 
Air adjustment screw
Throttle cable adjustment nuts 
Throttle cable adjustment nuts










