Checking The Spark Advance - PIAGGIO MSS ZIP 100 4T Service Manual

MSS ZIP 100 4T

Checking the spark advance

The vehicle is fitted with a variable advance electronic device. There are two timing references on the
flywheel cover in order to ensure a better precision when detecting the reference on the fan. Use a
Tecnotest 130/P stroboscopic gun or a similar device to check. Start the engine and rev it to 1800 rpm
(engine idle speed), operate the phase shifter and align the reference on the flywheel fan in between
the two references done on the cover; at the same time read the advance value shown in the strobo-
scopic gun display; the value must be 10°. Repeat the operation with the engine at 5000 ÷ 6000 rpm;
the advance read must be 17°.
CAUTION
SHOULD THE FLASH INDICATIONS BE UNSTABLE AND THE RPM INDICATION DOES NOT
CORRESPOND WITH THE TRUE ENGINE SPEED VARIATION (FOR EXAMPLE, VALUES SHOWN
ARE HALVED), INSTALL A 10 ÷ 15 KΩ RESISTIVE CABLE CONNECTED IN SERIES TO AN HV
CABLE. IF THE IRREGULAR READING CONTINUES AFTER THIS OPERATION, CHECK THE
COMPONENTS OF THE IGNITION SYSTEM.
N.B.
WHEN THE INDUCTION CLAMP READS THE SIGNAL CORRECTLY, A READING CAN BE CAR-
RIED OUT AT OVER 6000 RPM.
Specification
1 spark on 7
1 spark on 3
all sparks are suppressed
REVOLUTION LIMITER
Maintenance
Desc./Quantity
10300 Rpm
10400 Rpm
10500 Rpm
MAIN - 29