The excs is operated by the signal supplied from the ecm. The open/close operation of the excv is performed by the excva which is controlled by the ecm by changing the current direction of the actuator motor. The position sensor (incorporated in the excva) detects the excva movement by measuring the voltage and then the ecm determines the excv opening angle based on the engine rpm and gear positions. Every time the ignition switch is turned on, the excva automatically drives the excv and detects full close/open position voltages and sets the excv to middle position.
Full close

Full open

Exhaust control system descriptionTurn signal / side-stand relay removal and
installation
Removal
Turn the ignition switch off.
Remove the frame cover assembly. Refer to “exterior parts removal and
installation” in section 9d .
Remove the turn signal/side-stand relay (1).
Installation
Install the turn signal/side-stand relay in the reverse
order of removal ...
Precautions
Precautions for wheel and tire
Proper tire pressure and proper tire loading are important
factors. Over loading tire can lead to tire
failure and loss of motorcycle control.
Under-inflated tires make smooth cornering difficult, and
can result in rapid tire wear.
...
Piston ring removal and installation
Removal
Remove the piston. Refer to “engine bottom side disassembly” .
Carefully spread the ring opening with your thumbs
and then push up the opposite side of the 1st ring to
remove it.
Note
do not expand the piston ring excessively
since it is apt to be broken down. ...