PIAGGIO Liberty 50 4tempi 2008, Workshop Manual, Page: 35 / 195

6) Start up the engine and, before adjusting the
idle speed, ensure the oil temperature is between
70 and 80 °C.
7) Wait for a few minutes to let the temperature
stabilise.
8) Without ever activating the throttle and
through the idle screw, bring the engine speed to
1,950 ± 50 rpm.
9) Adjust the flow screw so to obtain a "CO" read-
ing of 3.2 % ± 0.5 %.
10) Slowly twist the throttle handgrip, bringing the
engine up to a speed of 4,000 rpm and then re-
lease it; check the idle speed is the same as be-
fore, otherwise repeat the operations starting from
point (3).
Specific tooling
020332Y Digital rpm indicator
494929Y Exhaust fumes analyser
020331Y Digital multimeter
Checking the end compression pressure
- With the engine cold remove the sparkplug cap.
- Remove the sparkplug.
- Fit a compression testing pressure gauge in the sparkplug seat with a sparkplug fitting and tighten it.
- Run the motor using the starter and with the carburetor fully open, until the reading on the pressure
gauge is stable.
- If the pressure is normal, remove the device and disassemble in the opposite order.
- If the pressure readings are below those indicated, check the engine rpm used for the test, if it is low
check the starter system, if the number of rpm is perfect or slightly above make sure the correct seal
has been chosen for the cylinder base and check the seals of the thermal part (elastic bands - valves
etc. head cylinder cap and distribution.
N.B.
IF YOU HAVE A HARD TIME INSERTING THE PRESSURE GAUGE FITTING, DISCONNECT THE
ENGINE - SWING ARM CONNECTION PIN AND PULL BACK THE ENGINE AS REQUIRED TO
INSERT THE FITTING.
Characteristic
sparkplug fitting
10 mm
Compression end pressure: Engine rpm
Liberty 50 4tempi
Maintenance
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