When the engine is running, the air intake valve is lifting up.
If the valve does not operate properly, check the air intake solenoid valve hoses for leak.
If there are no leaks, check the air intake solenoid valve.

Air Intake Solenoid Valve Unit TestCaliper Fluid Seal Damage
The fluid seal (piston seal) [A] is placed around the piston
to maintain clearance between the pad and the disc. If
the seal is in a poor condition, it could lead the pad to wear
excessively or the brake to drag, which may cause the temperature
of the discs or the brake fluid to increase.
Re ...
Exhaust Butterfly Valve Actuator Inspection
NOTE
Be sure the battery is fully charged
Remove the front seat (see Front Seat Removal in the
Frame chapter).
Turn the ignition switch to ON.
In the left side view of the motorcycle, check to see
the pulley [A] clockwise [B] and counterclockwise [C]
smoothly.
The pulley turns ...
Throttle Body Assy Installation
Apply a thin coat of grease to the throttle cable lower ends.
Fit the accelerator cable end [A] and the decelerator cable
end [B] into the throttle pulley.
Install the clamp [C] securely.
Install the throttle body assy holder clamp bolt heads [A]
outside as shown in the figure.
...