PIAGGIO Liberty 125, Workshop Manual, Page: 136 / 212

~ 15
Ω
Adjusting the idle
- The engine does not need frequent idle adjust-
ments, however it is very important to make any
adjustments fully respecting some standards.
- Before adjusting the carburettor make sure to re-
spect the lubrication requirements, valve clear-
ance, and complying timing, spark plug should be
in optimum conditions, air filter clean and sealed,
and the exhaust system tight.
- Warm up the engine by running it at least 5 mi-
nutes at approximately 50 kph.
- Connect the vehicle to the exhaust fumes analy-
ser inserting the probe into a sealed extension pipe
placed at the muffler exit end.
- Connect a millimetre thermometer (020331y) on
the sump, using a cover with oil expressly pre-
pared for probes.
- Start the motor and before adjusting the idle
speed make sure that the oil temperature is be-
tween 70 ÷ 80°C.
- Using the rpm indicator or any other instrument
(020332y), adjust the idle screw to obtain 1600
rpm ÷ 1700 rpm
- Adjust the flow screw until the carbon monoxide
(CO) percentage is 3.1 ÷ 4.5%, when the screw is
loosened the CO value rises (rich mix). Tightening
the screw decreases the CO (lean mix).
- If the adjustment of the flow screw causes a rpm
increase readjust the revs again and if necessary,
the flow screw to reach stable values.
- When the oil temperature, the numbers of revs
and the percentage of carbon monoxide are re-
spected the idle carburetion is considered correct.
From the analyser we can draw further informa-
tion:
Engine
Liberty 125 - 200 4tempi
ENG - 136