Yamaha YZF-R125 Service Manual: Valves and valve springs

Installing the camshaft and rocker arms

1. Lubricate: Rocker arms Rocker arm shafts 2. Lubricate: Camshaft 3. Install: Camshaft "1" NOTE: Make sure that the camshaft projections "a" and hole "b" are positioned as s ...

Removing the valves

The following procedure applies to all of the valves and related components. NOTE: Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure th ...

Other materials:

Setting the normal mode
NOTE: The engine speed, coolant temperature, and fault code, if detected, can be displayed on the LCD of the FI diagnostic tool when the tool is connected to the vehicle and is set to the normal mode. 1. Set the main switch to "OFF" and the engine stop switch to "". 2. Disconnect the self- ...

Troubleshooting method
The engine operation is not normal and the engine trouble warning light comes on. 1. Check: Fault code number a. Check the fault code number displayed on the FI diagnostic tool. b. Identify the faulty system with the fault code. Refer to "Self-Diagnostic Function table". c. Identi ...

Checking the drive sprocket
1. Check: Drive sprocket More than 1/4 tooth "a" wear Replace the drive chain sprockets as a set. Bent teeth Replace the drive chain sprockets as a set. b. Correct 1. Drive chain roller 2. Drive chain sprocket Checking the rear wheel sprocket Refer to "CHECKING AND R ...