PIAGGIO B 250 - Page 56

CHECK THAT THE RESULT IS OBTAINED WITH THE
VALVE GAS IN CLOSED POSITION.
N.B.
ALSO CHECK THE CARBURETION ADJUSTMENT IS OB-
TAINED WITH THE FLOW SCREW OPEN BETWEEN 2 AND
4 TURNS.
N.B.
OTHERWISE, CHECK THE FUEL LEVEL ADJUSTMENT IN
THE TANK AND THE FUEL CIRCUIT.
N.B.
IN CASE OF UNSTABLE CO, CHECK THAT THE CARBU-
RETTOR IS CLEAN AND THAT THE FUEL SUPPLY SYS-
TEM AND THE DEPRESSION SEALS WORK ADEQUATE-
LY
N.B.
IN CASE OF 1000 PPM UNBURNED HYDROCARBONS
(HC) >, CHECK THE IGNITION SYSTEM, THE TIMING SYS-
TEM, THE VALVE CLEARANCE AND THE EXHAUST
VALVE TIGHTNESS.
Specific tooling
020329Y MityVac vacuum-operated pump
020332Y Digital rev counter
494929Y Exhaust fumes analyser
020625Y Kit for sampling gas from the exhaust
manifold
Characteristic
CO Check
3.8±0.7 to 1650±50 RPM
SAS filters inspection and cleaning
ENGINE 250
- Remove LHS footrest.
- Remove the air-box/crankcase fixing screws.
- Remove the three fixings shown in the figure.
- Detach the oil vapours recovery line and the choke cable harness from the clamp shown in the picture.
- Remove the plastic fairing.
Maintenance B 125-250
MAIN - 56