Kubota D650-B Handbuch Seite 150

[AI How to repair the valve seat
/
/
(2)
[AI Finishing size of inlet valve guide
[Bl Finishing size of exhaust valve guide
~75F035
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Repairing the Valve Seat
1) Clean the valve seat surface.
2) Use a 45" cutter suitable for the valve guide and the valve
seat.
3) Grind the upper surface of valve seat with 15° cutter so
that the valve seat fits to the valve center (so as to ensure
a b as shown in the figure).
(Note)
• After correcting the valve seat, check for valve recessing.
A 45° cutter B 15° cutter
(11
Valve
(21 Corrected surface of valve seat
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Checking Valve Recessing
1) Clean the face of the valve.
2) Measure the recessing with a depth gauge.
0.9 to 1.1 mm
Reference
0.035 to 0.043 in.
1.3 mm
Allowable limit
0.051 in.
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Checking Guide Clearance
1) Remove carbon from the valve guide.
2) After making sure that the valve stem is straight, insert the
valve into the valve guide.
3) Measure the stem guide clearance with a dial gauge.
4) If the measurement exceeds the allowable limit. replace
the stem guide and the valve.
(Important)
• When changing the valve guide, be sure to ream as the
figure indicates after inserting the valve guide.
Allowable limit
0.004 in.
(1) 7.010 to 7.025mm
0.2760 to 0.2766 in.
(21 7.010 to 7.025mm
0.2760 to 0.2766 in.
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