Adjusting Valve Lapping; Checking Clearance Between Valve Stem And Valve Guide - Kubota WSM 05-E4B Series Workshop Manual

4. ENGINE
3. Measure the valve recessing with a depth gauge.
NOTE
• If the measurement is more than the service
limit, replace the valve.
• If it stays more than the service limit after
you replace the valve, replace the cylinder
head.
Service specifica-
tion
Valve recessing
Service limit
(1) Cylinder head surface
(A) Recessing

6.5 Adjusting valve lapping

Tools required
• Compound
• Valve lapping tool
• Prussian Blue
1. Apply the compound equally to the valve lapping
surface.
2. Put the valve into the valve guide. Lap the valve on
its seat with a valve lapping tool.
3. After you lap the valve, clean away the compound
and apply oil, then lap the valve again with oil.
4-52
0.050 (protrusion) to
0.25 (recessing) mm
0.0020 (protrusion) to
0.00098 (recessing) in.
0.40 (recessing) mm
0.016 (recessing) in.
(B) Protrusion
4. Apply Prussian Blue to the contact surface to
measure the seated rate.
NOTE
• If the seated rate is less than 70%, lap the
valve again.
IMPORTANT
• After you complete the valve lapping and
assemble the
recessing and adjust the valve clearance.
(1) Good
(2) Bad
RELATED PAGE
10.1 Checking valve clearance on page 3-15
6.4 Checking valve recessing on page 4-51
6.6 Checking clearance between
valve stem and valve guide
Tools required
• Outside micrometer
• Inside micrometer
1. Remove carbon from the valve guide section.
SERVICING
6. Servicing
valve, check the valve
(3) Bad
05-E4B SERIES,05-E4BG SERIES
KiSC issued 03, 2023 A