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 TestFuel Hose Replacement
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
WARNINGFuel is flammable and explosive under
certain conditions
and can cause severe burns. Be prepared
for fuel spillage; any spilled fuel must be completely
wiped up immediately. When the fue ...
Turn Signal Relay Inspection
Remove the battery (see Battery Removal).
Take the turn signal relay [A] off the rear fender.
Disconnect the connector [B].
Connect one 12 V battery and turn signal lights as indicated
in the figure, and count how many times the lights
blink for one minute.
Turn Signal Relay ...
Vehicle-down Sensor Installation
Be sure to install the rubber dampers [A] and collars [B]
on the bracket.
The UP mark [A] of the sensor should face upward.
WARNINGIncorrect installation of the vehicle-down
sensor
could cause sudden loss of engine power. The
rider could lose balance during certain ...