Checking Clearance Between Valve Stem And Valve Guide; Replacing Valve Guide - Kubota D1803-CR-E4 Workshop Manual

SERVICING
7. Servicing
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
7.4 Checking valve recessing on page 4-164
4.2 Adjusting valve clearance on page 4-98
7.6 Checking clearance between
valve stem and valve guide
Tools required
• External micrometer
• Small hole gauge
1. Remove carbon from the valve guide section.
2. Measure the valve stem O.D. with an external
micrometer.
Service specifi-
Valve stem O.D.
cation
D1803-CR-E4,D1803-CR-TE4,D1803-CR-TIE4,V2403-CR-E4,V2403-CR-TE4,V2403-CR-TE4BG,V2403-CR-TIE4
valve, check the valve
(3) Bad
7.960 to 7.975 mm
0.3134 to 0.3139 in.
3. Measure the valve guide I.D. with a small hole
gauge.
Service specifi-
Valve guide I.D.
cation
4. Calculate the clearance.
NOTE
• If the clearance is more than the service
limit, replace the valves.
• If the clearance stays more than the service
limit, replace the valve guide also.
Service specifi-
Clearance be-
cation
tween valve stem
and valve guide
Service limit
RELATED PAGE
7.7 Replacing valve guide on page 4-165

7.7 Replacing valve guide

IMPORTANT
• Do not hit the valve guide with a hammer during
replacement.
4. ENGINE
8.015 to 8.030 mm
0.3156 to 0.3161 in.
0.040 to 0.070 mm
0.0016 to 0.0027 in.
0.10 mm
0.0039 in.
4-165
KiSC issued 12, 2018 A