Servicing; Cylinder Head And Valves - Kubota WSM L3560 Workshop Manual

L3560, L4060, L4760, L5060, L5460, L6060, WSM

7. SERVICING

[1] CYLINDER HEAD AND VALVES

Top Clearance
1. Remove the cylinder head.
2. With the piston at TDC, use grease to affix three or four
plastigauges (1) of a diameter 1.5 mm (0.059 in.) × 5.0 to
7.0 mm (0.20 to 0.27 in.) long to the crown of the piston; keep
the gauges away from the intake valve and combustion
chamber fittings.
3. Take the piston to an intermediate position, install the cylinder
head and tighten the head screws to the specified torque.
4. Turn the crankshaft so the piston goes through TDC.
5. Remove the cylinder head and compare the width of the
crushed plastigauges (2) with the scale (3).
6. If they are out of spec, check the oil clearance of the crank pin,
journals and piston pin.
NOTE
• Top clearance = Width of the crushed plastigauge (2).
Top clearance Factory specification
Tightening torque Cylinder head screws
(1) Plastigauge
(2) Crushed Plastigauge
Cylinder Head Surface Flatness
1. Clean the cylinder head surface.
2. Put a straightedge on the cylinder head.
3. Measure the clearance with a feeler gauge at the 6 places (see
the figure).
4. If the measurement is more than the allowable limit, make it
straight with a surface grinder.
IMPORTANT
• Do not put a straightedge on the combustion chamber.
• Examine the valve recessing after you correct.
Cylinder head surface
Allowable limit
flatness
1-S76
ENGINE
0.60 to 0.70 mm
0.024 to 0.027 in.
93.2 to 98.0 N·m
9.50 to 10.0 kgf·m
68.8 to 72.3 lbf·ft
(3) Scale
9Y1210824ENS0068US0
0.05 mm
0.002 in.
9Y1210824ENS0069US0
KiSC issued 03, 2016 A