Yamaha 2009 VMX17YC, Service Manual

Page: 287 / 583

CAMSHAFTS
5-14
TIP
While holding the camshaft sprocket and cam-
shaft gear with the rotor holding tool “1”, loosen
the camshaft sprocket bolts and camshaft gear
bolts.
Front cylinders
TIP
When removing the front cylinder camshafts, re-
peat the rear cylinder camshaft removal proce-
dure. However, note the following points.
1. Position:
• Piston #2
(at TDC)
▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼▼▼
a. Position piston #2 at TDC by turning the
crankshaft counterclockwise until the “T2”
mark “a” on the generator rotor is aligned with
the stationary pointer “b” on the generator
cover.
TIP
TDC on the compression stroke can be found
when the “I” mark “c” in the intake camshaft gear
(front cylinders) is aligned with the edge of the
cylinder head “d”
▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲▲▲
EAS23850
CHECKING THE CAMSHAFTS
The following procedure applies to all of the
camshafts.
1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches
→
Re-
place the camshaft.
2. Measure:
• Camshaft lobe dimensions “a” and “b”
Out of specification
→
Replace the camshaft.
Rotor holding tool
90890-01235
Universal magneto & rotor holder
YU-01235
1
T2
a b
Camshaft lobe dimensions
Intake A
32.850–32.950 mm (1.2933–
1.2972 in)
Limit
32.750 mm (1.2894 in)
Intake B
24.131–24.231 mm (0.9500–
0.9540 in)
Limit
24.031 mm (0.9461 in)
Exhaust A
32.850–32.950 mm (1.2933–
1.2972 in)
Limit
32.750 mm (1.2894 in)
Exhaust B
24.131–24.231 mm (0.9500–
0.9540 in)
Limit
24.031 mm (0.9461 in)
c
d