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:

Checking the shift forks
The following procedure applies to all of the shift forks. 1. Check: Shift fork cam follower "1" Shift fork pawl "2" Bends/damage/scoring/wear Replace the shift fork. 2. Check: Shift fork guide bar Roll the shift fork guide bar on a flat surface. Bends  Replace. ...

Identification numbers
Record the key identification number, vehicle identification number and model label information in the spaces provided below for assistance when ordering spare parts from a Yamaha dealer or for reference in case the vehicle is stolen. KEY IDENTIFICATION NUMBER: VEHICLE IDENTIFICATION ...

Checking the camshaft sprocket and timing chain guide
1. Check: Camshaft sprocket More than 1/4 tooth wear "a" Replace the camshaft sprocket, timing chain and crankshaft as a set. a. 1/4 tooth b. Correct 1. Timing chain roller 2. Camshaft sprocket 2. Check: Timing chain guide (exhaust side) Damage/wear Replace. ...