Yamaha YZF-R125 Service Manual: Checking the rocker arms and rocker arm shafts

Yamaha YZF-R125 Service Manual / Engine / Camshaft / 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:

Rocker arm inside diameter "a" Out of specification Replace.

Checking the rocker arms and rocker arm shafts

4. Measure:

Rocker arm shaft outside diameter "a" Out of specification Replace.

Checking the rocker arms and rocker arm shafts

5. Calculate:

Rocker-arm-to-rocker-arm-shaft clearance

NOTE:

Calculate the clearance by subtracting the rocker arm shaft outside diameter from the rocker arm inside diameter.

Out of specification Replace the
defective part(s).

Checking the camshaft

1. Check: Camshaft lobes Blue discoloration/pitting/scratches Replace the camshaft. 2. Measure: Camshaft lobe dimensions "a" and "b" Out of specification Replace the cams ...

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 ...

Other materials:

Faulty front fork legs
Leaking oil - Bent, damaged or rusty inner tube - Cracked or damaged outer tube - Improperly installed oil seal - Damaged oil seal lip - Incorrect oil level (high) - Loose damper rod assembly bolt - Damaged damper rod assembly bolt copper washer - Cracked or damaged front fork cap O-ring M ...

Adjusting the clutch lever free play
Adjusting the clutch lever free play Clutch lever free play adjusting bolt Clutch lever free play The clutch lever free play should measure 10.0-15.0 mm (0.39-0.59 in) as shown. Periodically check the clutch lever free play and, if necessary, adjust it as follows. Slide the ...

Installing the water pump
1. Install: Water pump assembly "1" O-rings "2" NOTE: Align the projection "a" on the impeller shaft with the slit "b" on the camshaft sprocket bolt. Lubricate the O-rings with a thin coat of lithiumsoap- based grease. 2. Fill: Cooling system (with the specified amou ...