cap.13 EU65is 6500is 07.12.17 5:05 PM ページ13-4
• VALVE STEM O.D.
Inspect each valve for face irregularities, bending or abnormal
stem wear. Replace the valve if necessary. Measure and record
each valve stem O.D.
Standard
6.575 – 6.590 mm
IN
(0.2589 – 0.2594 in)
6.535 – 6.550 mm
EX
(0.2573 – 0.2579 in)
Replace the valves if their O.D. is smaller than the service limit.
• VALVE GUIDE I.D.
Ream the valve guide to remove any carbon deposits before
measuring.
Measure and record each valve guide I.D.
Standard
6.600 – 6.615 mm
IN/EX
(0.2598 – 0.2604 in)
Replace the guides if they are over the service limit.
TOOL:
Valve guide reamer, 6.612 mm
• GUIDE-TO-STEM CLEARANCE
Subtract each valve stem O.D. from the corresponding guide
I.D. to obtain the stem-to-guide clearance.
Standard
0.010 – 0.040 mm
IN
(0.0004 – 0.0016 in)
0.050 – 0.080 mm
EX
(0.0020 – 0.0031 in)
If the stem-to-guide clearance exceeds the service limit,
determine if the new guide with standard dimensions would
bring the clearance within tolerance. If so, replace any guide as
necessary and ream to fit. If the stem-to-guide clearance
exceeds the service limit with new guides, replace the valves
as well.
Recondition the valve seats whenever the valve guides are
replaced (P. 13-6 and 7).
13-4
Service limit
6.44 mm
(0.2535 in)
6.40 mm
(0.2520 in)
Service limit
6.66 mm
(0.2622 in)
07984-ZE20001
Service limit
0.11 mm
(0.004 in)
0.13 mm
(0.005 in)
[1]
VALVE GUIDE
REAMER, 6.612 mm
07984-ZE20001