No Spark Plug - PIAGGIO X8 125 Workshop Manual

X8 125-200

No spark plug

Once the lack of power to the spark plug has been
detected and the LED indicates it can be ignited,
follow this procedure:
- Pick-Up check.
Disconnect the control unit connector and check
that the cable between terminal No. 2 (Green) and
terminal No. 8 (Black) is not interrupted. Check the
Pick-Up and its power line:
Electric characteristic
Pick-up resistance value
Pick-up resistance value: 105 ÷ 124 Ohm
If a break in the circuit is found, check again the flywheel and the engine ground connectors (see engine
manual). If non-conforming values are detected, replace the Pick-Up, otherwise check the cable har-
ness and the connections. In case conforming values are measured and the wiring and connections
check is OK, try replacing the control unit (without programming) and make sure the failure has been
solved by checking sparks are produced in the spark plug; only then program the control unit. If no
sparks are produced with the new control unit, proceed as follows.
- HV primary coil check
Disconnect the two connectors on the HV coil and
check continuity (see figure). If non-conforming
values are measured, replace the HV coil. If con-
forming values are measured, check the cable
harness taking into account that the HV coil posi-
tive wire has a branch that comes into the digital
instrument panel (violet cable). Therefore, make
sure this line is in perfect conditions. If failures are
detected, check the HV coil secondary.
Electric characteristic
High voltage coil primary resistance value
High voltage coil primary resistance value: 0.4 ÷
0.5 Ohm
HV coil secondary check
Disconnect the spark plug cap from the HV cable and measure the resistance between the HV cable
terminal and the HV coil negative terminal (see figure). If non-conforming values are measured, replace
the HV coil. To carry out a more complete diagnosis, check the peak voltage with the multimeter adaptor.
Electric characteristic
Electrical system
ELE SYS - 75