Yamaha YZF-R125 Service Manual: Troubleshooting

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: ...

Charging system

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Other materials:

Troubleshooting
The ignition system fails to operate (no spark or intermittent spark). NOTE: Before troubleshooting, remove the following part(s): 1. Seats 2. Fuel tank 3. Right side cover 4. Left side panel 5. Left upper side cowling ...

Checking the rocker arms and rocker arm shafts
The following procedure applies to all of the rocker arms and rocker arm shafts. 1. Check: Rocker arm Damage/wear Replace. 2. Check: Rocker arm shaft Blue discoloration/excessive wear/pitting/ scratches  Replace or check the lubrication system. 3. Measure: Rocke ...

Replacing the air filter element and cleaning the check hose
The air filter element should be replaced at the intervals specified in the periodic maintenance and lubrication chart. Have a Yamaha dealer replace the air filter element more frequently if you are riding in unusually wet or dusty areas. In addition, the air filter check hose must be ...