Kubota D902-E2B - Cylinder Head and Valves; Cylinder Head Surface Flatness; Servicing; Top Clearance

S-53
SM-E2B SERIES, WSM
DIESEL ENGINE
[3] SERVICING
(1) Cylinder Head and Valves
Top Clearance
1. Remove the cylinder head. (Do not attempt to remove the
cylinder head gasket.)
2. Move the piston up and stick a strip of fuse [1.5 mm dia. (0.059
in. dia.), 5 to 7 mm long (0.197 to 0.276 in. long)] on the piston
head at three positions with grease so as to avoid the intake and
exhaust valves and the combustion chamber ports.
3. Lower the piston, and install the cylinder head and tighten the
cylinder head screws to the specified torque.
4. Turn the flywheel until the piston exceeds top dead center.
5. Remove the cylinder head, and measure the thickness of the
squeezed fuses.
6. If the measurement is not within the factory specifications, check
the oil clearance between the crankpin and crankpin bearing and
between the piston pin and small end bushing.
NOTE■
• After checking the top clearance, be sure to assemble the
cylinder head with a new cylinder head gasket.
W1020190
Cylinder Head Surface Flatness
1. Clean the cylinder head surface.
2. Place a straightedge on the cylinder head’s four sides and two
diagonal as shown in the figure.
3. Measure the clearance with a thickness gauge.
4. If the measurement exceeds the allowable limit, correct it with a
surface grinder.
IMPORTANT■
• Do not place the straightedge on the combustion chamber.
• Be sure to check the valve recessing after correcting.
W1027737
Top clearance Factory spec.
0.50 to 0.70 mm
0.0197 to 0.0276 in.
Tightening torque Cylinder head screw
37.3 to 42.2 N·m
3.8 to 4.3 kgf·m
27.5 to 31.1 ft-lbs
(1) Fuse
Cylinder head surface
flatness
Allowable limit
0.05 mm
0.0020 in.
KiSC issued 06, 2006 A