Servicing; Cylinder Head And Valves - Kubota WG1605-G-E3 Workshop Manual

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

[3] 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 bolts 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,
journal and piston pins.
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. Place a straightedge on the cylinder head's four sides and two
diagonal 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-S40
ENGINE
1.2 to 1.5 mm
0.048 to 0.059 in
63.7 to 68.6 N·m
6.50 to 6.99 kgf·m
47.0 to 50.5 lbf·ft
(3) Scale
9Y1210661ENS0068US0
0.05 mm
0.002 in.
9Y1210318ENS0087US0
KiSC issued 05, 2014 A