Kubota B1220 Workshop Manual page 109

B1220, B1620, B1820, WSM
Cylinder Head Flaw
1. Prepare an air spray red check.
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.
(1) Red Permeative Liquid
(2) Detergent
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.
Factory specification
Valve recessing
(Intake and exhaust)
Allowable limit
(1) Cylinder Head Surface
Clearance between Valve Stem and Valve Guide
1. Remove carbon from the valve guide section.
2. Measure the valve stem O.D. with an outside micrometer.
3. Measure the valve guide I.D. with a small hole gauge, and
calculate the clearance.
4. If the clearance exceeds the allowable limit, replace the valves.
If it still exceeds the allowable limit, replace the valve guide.
Factory specification
Clearance between
valve stem and valve
guide
Allowable limit
Valve stem O.D. Factory specification
Valve guide I.D. Factory specification
1-S40
ENGINE
(3) White Developer
9Y1210272ENS0058US0
−0.10 (protrusion) to 0.10
(recessing) mm
−0.0039 (protrusion) to
0.0039 (recessing) in.
0.30 (recessing) mm
0.012 (recessing) in.
(A) Recessin
(B) Protrusion
9Y1210272ENS0059US0
0.030 to 0.057 mm
0.0012 to 0.0022 in.
0.10 mm
0.0039 in.
5.968 to 5.980 mm
0.2350 to 0.2354 in.
6.010 to 6.025 mm
0.2367 to 0.2372 in.
9Y1210272ENS0060US0
KiSC issued 07, 2011 A
(EU)