Yamaha YZF-R125 Service Manual: Starting circuit cut-off system operation

If the engine stop switch is set to " " and the main switch is set to
"ON" (both switches are closed), the starter motor can only operate if at least one of the following conditions is met:

• The transmission is in neutral (the neutral switch is closed).
• The clutch lever is pulled to the handlebar (the clutch switch is closed) and the sidestand is up (the sidestand switch is closed).

The starting circuit cut-off relay prevents the starter motor from operating when neither of these conditions has been met. In this instance, the starting circuit cut-off relay is open so current cannot reach the starter motor. When at least one of the above conditions has been met, the starting circuit cut-off relay is closed and the engine can be started by pressing the start switch " 
".

a. WHEN THE TRANSMISSION IS IN NEUTRAL

b. WHEN CLUTCH LEVER IS PULLED TO THE HANDLEBAR AND THE SIDESTAND IS UP

1. Battery

2. Main fuse

3. Main switch

4. Ignition fuse

5. Engine stop switch

6. Starting circuit cut-off relay

7. Clutch switch

8. Sidestand switch

9. Diode

10.Neutral switch

11.Start switch

12.Starter relay

13.Starter motor