PIAGGIO 500 cc Service Manual page 175

During the 30 seconds of pump diagnosis, feed the
injector via the wire and the auxiliary battery
for 15 seconds.
Using the measuring container, collect the fuel
distributed from the injector.
Supply pressure = 300 KPa (3 BAR)
Quantity supplied = around 40 cm
Proceed with the injector seal test.
Dry the injector outlet with a jet of compressed air.
Activate the fuel pump. Wait one minute, check that
there is no loss from the injector outlet. A slight
oozing is normal.
Limit value = 1 drop per minute
The injector is conformant
Atomization of the injector cannot be checked with
simple systems. The injector is supplied with 5 holes
whose gradient form gives a jet with taper of around
80°. Formed in this manner, the jet covers both the air
intake valves.
NOTE:
- An injector with low flow capacity influences the
maximum performance.
- And injector with poor seal mainly influences idling
and ignition characteristics after parking briefly with
the engine warm.
- On discovering occlusion of the injector, proceed with
replacement of the injector, filter and the fuel tank
contents. Clean the system and the tank accurately.
3
YES
YES
Higher quantities are not plausible.
For lesser quantities proceed with replacement of
the injector. (see Chapter. 7-THERMAL UNIT
AND TIMING SYSTEM)
Repeat the test. If the anomaly persists
replace the injector. (see Chapter. 7-
THERMAL UNIT AND TIMING SYSTEM)
NO
80°
Fuel injection
NO
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