Yamaha YZ 2020 Series, Owner'S Service Manual

Page: 207 / 376

CAMSHAFT
5-20
shaft caps, and camshaft will result.
2. Install:
•
Timing chain tensioner
a. While pressing the tensioner rod lightly
with your fingers, use a thin screwdriver to
wind the tensioner rod up fully clockwise.
b. With the tensioner rod fully wound and the
chain tensioner “UP” mark “a” facing up-
ward, install the gasket “1”, the timing
chain tensioner “2” and tighten the bolts
“3”.
c. Release the screwdriver, check that the
tensioner rod comes out smoothly, and
tighten the gasket “4” and the cap bolt “5”.
3. Turn:
• Crankshaft
Counterclockwise several turns.
4. Check:
•
Top dead center (TDC) mark on the genera-
tor rotor
Align with the crankcase alignment mark.
• Camshaft match marks
Align with the cylinder head surface.
Out of alignment

Adjust.
5. Install:
• Timing chain guide (top side) “1”
•
Cylinder head cover gasket “2”
• Cylinder head cover “3”
•
Bolt (cylinder head cover) “4”
TIP
Before installation, apply the sealant to the cylin-
der head cover gasket.
6. Install:
•
Cylinder head breather hose
• Spark plug
Bolt (timing chain tensioner)
10 N·m (1.0 kgf·m, 7.4 lb·ft)
Tensioner cap bolt
6 N·m (0.6 kgf·m, 4.4 lb·ft)
1 1 1 2 2
3 3 4 4
6 6 5 5
8 8 7 7
E
T
R
.
.
2 2 2
a a
3 3
1 1
3 3
T
R
.
.
Bolt (cylinder head cover)
10 N·m (1.0 kgf·m, 7.4 lb·ft)
Yamaha bond No. 1215
90890-85505
(Three bond No.1215®)
Spark plug
13 N·m (1.3 kgf·m, 9.6 lb·ft)
4 4 4
5 5
New
T
R
.
.
1
3
4
2
T
R
.
.