Servicing; Cylinder Head And Valves - wsm M6040 Workshop Manual

M6040, M7040, WSM

[6] SERVICING

(1) Cylinder Head and Valves

Top Clearance
1. Remove the cylinder head (remove the cylinder head gasket
completely).
2. Bring the piston to its top dead center fasten 1.5 mm dia. 5 to
7 mm long fuse wires to 3 to 4 spots on the piston top with
grease so as to avoid the intake and exhaust valves and the
combustion chamber ports.
3. Bring the piston to its middle position, install the cylinder head,
and tighten the cylinder head screws to specification. (Head
gasket must be changed to new one).
4. Turn the crank shaft until the piston exceeds its top dead center.
5. Remove the cylinder head, and measure squeezed fuse wires
for thickness.
6. If the measurement is not within the specified value, check the
oil clearance of the crankpin journal and the piston pin.
Top clearance Factory specification
Cylinder head mounting
Tightening torque
screw
(1) Fuse
Cylinder Head Surface Flatness
1. Clean the cylinder head surface.
2. Place a straightedge on the cylinder head's four sides "A", "B",
"C" and "D" and two diagonal "E" and "F" as shown in the
figure.
Measure the clearance with a feeler gauge.
3. If the measurement exceeds the allowable limit, correct it with a
surface grinder.
IMPORTANT
• Be sure to check the valve recessing after correcting.
Cylinder head surface
Allowable limit
flatness
1-S61
ENGINE
0.60 to 0.80 mm
0.0236 to 0.0315 in.
187 to 196 N·m
19.0 to 20.0 kgf·m
138 to 144 lbf·ft
9Y1210143ENS0086US0
0.05 mm
0.0020 in.
9Y1210143ENS0087US0
KiSC issued 07, 2012 A