the clutch switch is on the handlebar, behind the clutch lever. It is part of the start sequence, kick stand up, clutch in before it runs. Some have been known to bypass both to make life easier... however, the ECU needs to see at least one clutch actuation to work correctly.... otherwise it is stuck in Neutral mode, will not fuel the motor properly, if you have upper and lower injectors, only the lower will function. It is kind of like being in limp mode.