There are three types of alternator failures: short, open (wire burned out), or loss in rotor magnetism. A short or open in one of the coil wires will result in either a low output, or no output at all. A loss in rotor magnetism, which may be caused by dropping or hitting the alternator, by leaving it near an electromagnetic field, or just by aging, will result in low output.
Turn the ignition switch to OFF.
Remove the left upper inner fairing (see Upper Inner Fairing Removal in the Frame chapter).
Disconnect the alternator lead connector [A].
Connect the hand tester as shown in the table 1.

Special Tool - Hand Tester: 57001-1394
Start the engine.
Run it at the rpm given in the table 1.
Note the voltage readings (total 3 measurements).
Table 1 Alternator Output Voltage at 4 000 r/min (rpm)

If the output voltage shows the value in the table, the alternator operates properly. The regulator/rectifier is damaged.
If the output voltage shows a much lower reading than that given in the table, stop the engine and inspect the stator coil resistance.
Stop the engine.
Connect the hand tester as shown in the table 2.
Special Tool - Hand Tester: 57001-1394
Table 2 Stator Coil Resistance at 20°C (68°F)
If there is more resistance than shown in the table, or no hand tester reading (infinity) for any two leads, the stator has an open lead and must be replaced. Much less than this resistance means the stator is shorted, and must be replaced.
Any hand tester reading less than infinity (∞) indicates a short, necessitating stator replacement.
If the stator coil has normal resistance, but the voltage check showed the alternator to be defective; then the rotor magnets have probably weakened, and the rotor must be replaced.
Charging Voltage Inspection
Regulator/Rectifier InspectionAir Cleaner
A clogged air cleaner restricts the engine’s
air intake, increasing fuel consumption,
reducing engine power, and
causing spark plug fouling.
This motorcycle’s air cleaner element
consists of a wet paper filter, which cannot
be cleaned.
The air cleaner element must be replaced
in acco ...
Exhaust Device
This motorcycle is equipped with a
exhaust device system. This system
controls the valve in the exhaust pipe
and produces stable engine power at
low and middle engine speed. This exhaust
device is controlled by the ECU,
and adjustment or maintenance should
be done only by a competent mechanic ...
Before Servicing
Before starting to perform an inspection service or carry out a disassembly
and reassembly operation
on a motorcycle, read the precautions given below. To facilitate actual
operations, notes, illustrations,
photographs, cautions, and detailed descriptions have been included in each
chapter w ...