Yamaha YXR660FAS Service Manual download pdf (Page 149)

4 - 19

ENG

CAMSHAFT AND CYLINDER HEAD

REMOVING THE CAMSHAFT AND

CYLINDER HEAD

1. Loosen:

• camshaft sprocket bolts 1

2. Loosen:

• timing chain tensioner cap bolt

3. Remove:

• timing chain tensioner

• timing chain guide (exhaust side)

• decompressor cam guide plates

• camshaft sprocket

• camshaft

NOTE:

• Fasten a safety wire to the timing chain to

prevent it from falling into the crankcase.

• When removing the camshaft sprocket, it is

not necessary to separate the timing chain.

4. Remove:

• cylinder head

NOTE:

• Loosen the bolts in the proper sequence.

• Follow the numerical order shown in the illus-

tration. Loosen each bolt 1/4 of a turn at a

time until all of the bolts are loose.

CHECKING THE CAMSHAFT

1. Check:

• cam lobes

Pitting/scratches/blue discoloration →

Replace.

2. Measure:

• cam lobe dimensions a and b

Out of specification → Replace.

Camshaft lobe limit

Intake

a

35.59 mm (1.4012 in)

b

29.96 mm (1.1795 in)

Exhaust

a

36.40 mm (1.4331 in)

b

30.01 mm (1.1815 in)

1 2 ... 144 145 146 147 148 149 150 151 152 153 154 ... 420 421

Comments to this Manuals

No comments