Removing The Camshafts; Removing The Rocker Arms And Rocker Arm Shafts; Checking The Camshafts - Yamaha YZF-R1 2020 Service Manual

EAS30256

REMOVING THE CAMSHAFTS

1. Remove:
• Timing mark accessing bolt
• Crankshaft end cover
Refer to "GENERATOR" on page 5-43.
2. Align:
• Mark "a" on the generator rotor
(with the generator rotor cover slot "b")
a. Turn the crankshaft counterclockwise.
b. When piston #1 is at BTDC105° on the
compression stroke, align the BTDC105°
mark "a" on the generator rotor with the
generator rotor cover slot "b".
TIP
BTDC105° on the compression stroke can be
found when the camshaft lobes are turned away
from each other.
3. Remove:
• Timing chain tensioner
• Timing chain tensioner gasket
4. Remove:
• Camshaft cap
ECA13720
NOTICE
To prevent damage to the cylinder head,
camshafts or camshaft caps, loosen the
camshaft cap bolts in stages and in a criss-
cross pattern, working from the outside in.
5. Remove:
• Intake camshaft
• Exhaust camshaft
TIP
To prevent the timing chain from falling into the
crankcase, fasten it with a wire "1".
EAS31655
REMOVING THE ROCKER ARMS AND
ROCKER ARM SHAFTS
1. Remove:
• Rocker arm shaft bolt
• Straight plug
• Rocker arm shaft
• Rocker arm
b
EAS30257

CHECKING THE CAMSHAFTS

1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches → Re-
a
place the camshaft.
2. Measure:
• Camshaft lobe dimensions "a"
Out of specification → Replace the camshaft.
G088946
3. Measure:
• Camshaft runout
Out of specification → Replace.
5-23
CAMSHAFTS
Camshaft lobe dimensions
Lobe height (Intake)
35.291–35.391 mm (1.3894–
1.3933 in)
Limit
35.191 mm (1.3855 in)
Lobe height (Exhaust)
34.745–34.845 mm (1.3679–
1.3718 in)
Limit
34.645 mm (1.3640 in)
1