Yamaha XMAX YP125R - Service manual > Camshaft (YP250R)

Removing the rocker arms and camshaft
Removing the rocker arms and camshaft

Removing the rocker arms and camshaft

1. Straighten the lock plate tabs "a".

2. Remove:

Removing the rocker arms and camshaft

3. Remove:

TIP

Remove the rocker arm shafts with the slide hammer bolt "1" and weight "2".

Slide hammer bolt 90890-01083

Slide hammer bolt 6 mm YU-01083-1

Weight 90890-01084 YU-01083-3

Removing the rocker arms and camshaft

4. Remove:

TIP

Screw a M10 bolt "2" into the threaded end of the camshaft, and then pull out the camshaft.

Removing the rocker arms and camshaft

Checking the camshaft

1. Check:

Blue discoloration/pitting/scratches → Replace the camshaft.

2. Measure:

Out of specification → Replace the camshaft.

Camshaft lobe dimensions Intake A 37.051-37.151 mm (1.4587- 1.4626 in)

Limit 36.950 mm (1.4547 in)

Intake B 30.074-30.174 mm (1.1840- 1.1880 in)

Limit 29.974 mm (1.1801 in)

Exhaust A 37.053-37.153 mm (1.4588- 1.4627 in)

Limit 36.953 mm (1.4548 in)

Exhaust B 30.091-30.191 mm (1.1847- 1.1886 in)

Limit 29.991 mm (1.1807 in)

Checking the camshaft

Checking the camshaft

3. Check:

Obstruction → Blow out with compressed air.

Checking the rocker arms and rocker arm shafts

The following procedure applies to all of the rocker arms and rocker arm shafts.

1. Check:

Damage/wear → Replace.

2. Check:

Blue discoloration/excessive wear/pitting/ scratches → Replace or check the lubrication system.

3. Measure:

Out of specification → Replace.

Rocker arm inside diameter 12.000-12.018 mm (0.4724- 0.4731 in)

Limit 12.030 mm (0.4736 in)

Checking the rocker arms and rocker arm shafts

4. Measure:

Out of specification → Replace.

Rocker arm shaft outside diameter 11.981-11.991 mm (0.4717- 0.4721 in)

Limit 11.950 mm (0.4705 in)

Checking the rocker arms and rocker arm shafts

5. Calculate:

TIP

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).

Rocker-arm-to-rocker-arm-shaft clearance 0.009-0.037 mm (0.0004-0.0015 in)

Limit 0.080 mm (0.0031 in)

Installing the camshaft and rocker arms

1. Lubricate:

Recommended lubricant

Camshaft Molybdenum disulfide grease

Camshaft bearing

Engine oil

2. Lubricate:

Recommended lubricant

Rocker arm inner surface

Molybdenum disulfide grease

Rocker arm shaft

Engine oil

3. Install:

TIP

Make sure the exhaust rocker arm shaft is completely pushed into the cylinder head.

4. Install:

TIP

Insert a guide stud (8 mm) "2" into the stud-bolt hole in the cylinder head and install the intake rocker arm shaft as shown.

NOTICE

Make sure the threaded part of the rocker arm shaft faces out.

Installing the camshaft and rocker arms

5. Install:

Camshaft retainer bolt 8 Nm (0.8 m*kgf, 5.8 ft*lbf)

TIP

Bend the lock plate tabs along a flat side of the bolts "3".

Installing the camshaft and rocker arms

See also:

 Yamaha XMAX YP125R - Service manual > Cylinder head (YP250R)

Removing the cylinder head Removing the cylinder head

 Yamaha XMAX YP125R - Service manual > Valves and valve springs (YP250R)

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