Yamaha YZF-R125 Service Manual: Fuel pump system

Troubleshooting details

This section describes the measures per fault code number displayed on the FI diagnostic tool. Check and service the items or components that are the probable cause of the malfunction following t ...

Circuit diagram

4. Main fuse 5. Main switch 9. Battery 17.Engine stop switch 25.ECU (engine control unit) 30.Fuel pump 64.Ignition fuse ...

Other materials:

Checking the speed sensor
1. Check: Speed sensor output voltage Out of specification → Replace. a. Connect the pocket tester (DC 20 V) to the speed sensor coupler (wire harness end) as shown. Positive tester probe gray "1" Negative tester probe gray/black "2" b. Set the main switch to "ON". c. ...

Checking the friction plates
The following procedure applies to all of the friction plates. 1. Check: Friction plate Damage/wear Replace the friction plates as a set. 2. Measure: Friction plate thickness Out of specification Replace the friction plates as a set. NOTE: Measure the friction plate ...

Outline of the fi system
The main function of a fuel supply system is to provide fuel to the combustion chamber at the optimum air-fuel ratio in accordance with the engine operating conditions and the atmospheric temperature. In the conventional carburetor system, the air-fuel ratio of the mixture that is supplied t ...