Servicing; Cylinder Head - Kubota Z400-B Handbuch

SERVICING
[1] CYLINDER HEAD
Clearance
1.
Remove the nozzle holder and lower the piston in the
cylinder.
2. Insert a high-quality fuse from the nozzle holder hole on
the piston except where it faces the valve or the com ­
bustion chamber insert.
3. Rotate the flywheel until the piston is raised and lowered
again.
4. Take out the flattened fuse carefully and measure its
thickness with vernier calipers.
5. If the measurement is not within the specified values,
check the oil clearances of the crankpin journal and the
piston pin.
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Cylinder Head Surface Flatness
1. Clean the cylinder head surface.
2. Place the straight edge on the cylinder head and measure
the clearance with a feeler gauge at the positions shown
in the figure.
3. If the measurement exceeds the allowable limit, correct
it with a surface grinder .
• NOTE:
• Do not place a straight edge over the combustion chamber
insert.
Flatness
Factory specification
0.03 mm
0.0012 in.
Allowable limit
0.05 mm
0.0020 in.
Cylinder Head Surface Flaw
-_._
....
1.
Prepare an air spray red check (Code No.: 07909-31371).
2. Clean the cylinder head surface with the detergent (2).
3. Spray the cylinder head surface with the red permeative
liquid (1).
4. Wash away the red permeative liquid on the cylinder head
surface with the detergent (2).
5. Spray the cylinder head surface with the white developer
(3).
6. If any flaw is found such as a red mark, replace the
cylinder head.
S-85