Kubota GR1600EC2, Workshop Manual, Page: 102 / 241

1-S35
GR1600EC2, WSM ENGINE
[4] SERVICING
(1) Cylinder Head and Valves
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
Cylinder Head Flaw
1. Prepare an air spray red check (Code No. 07909-31371).
2. Clean the surface of the cylinder head with detergent (2).
3. Spray the cylinder head surface with the red permeative liquid
(1). Leave it five to ten minutes after spraying.
4. Wash away the read permeative liquid on the cylinder head
surface with the detergent (2).
5. Spray the cylinder head surface with white developer (3).
6. If flawed, it can be identified as red marks.
W1076542
Valve Recessing
1. Clean the cylinder head surface, valve face and valve seat.
2. Insert the valve into the valve guide.
3. Measure the valve recessing with a depth gauge.
4. If the measurement exceeds the allowable limit, replace the
valve.
5. If it still exceeds the allowable limit after replacing the valve,
replace the cylinder head.
W10768800
Cylinder head surface
flatness
Allowable limit
0.05 mm
0.0020 in.
(1) Red Permeative Liquid
(2) Detergent (3) White Developer
Valve recessing
(Intake and Exhaust)
Factory spec.
0.10 (protrusion) to
0.10 (recessing) mm
0.0039 (protrusion) to
0.0039 (recessing) in.
Allowable limit
0.30 (recessing) mm
0.0118 (recessing) in.
(1) Cylinder Head Surface (A) Recessing
(B) Protrusion
KiSC issued 07, 2006 A