Sym GTS 250 Service Manual page 28

Carburetor Idle Speed Adjustment
Caution
Inspection & adjustment for idle speed have
●
to be performed after all parts in engine that
needed adjustment have been adjusted.
Idle speed check and adjustment have to be
●
done after engine is being warm up. (It is
enough that operates engine from stop to
running for 10 minutes.)
Park the motorcycle with main stand and warm up
engine.
Connect tachometer (the wire clamp of tachometer
is connected to the high tension cable).
Open carburetor cover from the luggage box.
Turn the throttle valve stopper screw to specified
idle speed
Specified idle speed:1500±100 rpm¡ C
Emission adjustment in idle speed
Warm up the engine for around 10 minutes and
then conduct this adjustment.
Connect the tachometer onto engine.
Adjust the throttle valve stopper screw and let
engine runs in 1500±100 rpm.
Insert the exhaust sampling pipe of exhaust
analyzer into the front section of exhaust pipe.
Adjust the air adjustment screw so that emission
value in idle speed is within standard.
Slightly accelerate the throttle valve and release it
immediately. Repeat this for 2~3 times.
Read engine RPM and value on the exhaust
analyzer. Repeat step 2 to step 4 procedures
until measured value within standard.
Emission standardCO: 3. 0 %↓
HC: 2,000 P.P.M.↓
To this chapter contents
Ignition coil cable
Throttle valve stopper screw
Mixture air adjusting screw
2. Maintenance Information
2-7