PIAGGIO Beverly 500 i.e., Workshop Manual

Page: 172 / 382

N.B.
WHEN THE CO PERCENTAGE IS RIGHT AND THE CO2 PERCENTAGE DOES NOT FALL INTO
THE SPECIFIED VALUES, THE LAMBDA VALUE IS ALSO DISTORTED.
If this occurs, carefully check the exhaust system for adequate sealing.
When the CO percentage is correct and the HC (PPM) value exceeds the maximum limit allowed, check:
- spark plug
- valve clearance
- timing system phase
- outlet valves for sealing
When the control unit is replaced, reset TPS and pre-program the trimmer value of the original control
unit (if available) preventively.
In any case, check the CO value again.
Make sure the entire exhaust system is sealed.
Remove the intake cap on the exhaust pipe, connect the dissipater and the extension pipe.
Warm-up the engine and use an exhaust analyser to check the carburation of the idle speed, if neces-
sary, restore the correct setting using a scooter Tester, see «Adjusting idle carburation».
Specific tooling
020625Y Kit for sampling gas from the exhaust manifold
494929Y Exhaust fumes analyser
Connect the gas collection kit at the muffler outlet being careful to ensure that it is sealed and stable
by making sure the band is correctly fitted.
Transfer the connection of the exhaust gas analyser from the manifold collection extension pipe to the
extension pipe for the muffler outlet.
Use the exhaust collection kit for this connection.
Close the extension outlet for collection from the manifold to make sure air does not infiltrate.
Specific tooling
020623Y Pre-service gas extraction set
Check the exhaust emissions from the muffler (after the catalytic converter) with the engine warm and
idling.
STANDARD VALUES WITH THE ENGINE IDLING
Specification Desc./Quantity
CO = < di XXX %
CO2 = > di XXX %
HC = < di XXX ppm
O2 = XXX %
Lambda factor: XX
If the values measured are the same as those obtained with what was collected from the exhaust pipe,
increase the catalytic converter temperature keeping then engine at average rpm and repeat the idle
test.
Injection
Beverly 500 i.e.
INJEC - 172