Installing The Cylinder Head - Yamaha YFM250RX 2008 Service Manual

CYLINDER HEAD
b. Remove the screwdriver and slowly release
the timing chain tensioner rod.
c. Make sure that the timing chain tensioner
rod comes out of the timing chain tensioner
housing smoothly. If there is rough move-
ment, replace the timing chain tensioner.
3. Check:
• Cap bolt
• Copper washer
• Spring
• One-way cam
• Timing chain tensioner rod
Damage/wear → Replace the defective
part(s).

INSTALLING THE CYLINDER HEAD

1. Install:
• Cylinder head gasket
• Dowel pins
2. Install:
• Cylinder head
• Copper washers
• Cylinder head bolts
3. Tighten:
• Cylinder head bolts
Cylinder head bolt 226 mm (8.90 in)
24 Nm (2.4 m•kg, 18 ft•lb)
Cylinder head bolt 45 mm (1.77 in)
20 Nm (2.0 m•kg, 15 ft•lb)
NOTE: NOTE:
• Apply oil to the bearing surface of (upper) cyl-
inder head bolt.
Further, apply molybdenum disulfide grease
to thread part.
• Tighten the cylinder head bolts in the proper
tightening sequence as shown.
4. Install:
• Camshaft sprocket
• Dowel pin
• Timing chain
4-12
ENG