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.
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.
Replace the guides if they are over the service limit.
TOOL:
Valve guide reamer, 6.612 mm
07984-ZE20001
• GUIDE-TO-STEM CLEARANCE
Subtract each valve stem O.D. from the corresponding guide
I.D. to obtain the stem-to-guide clearance.
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).
[1]
VALVE GUIDE
REAMER, 6.612 mm
07984-ZE20001
Standard
Service limit
IN
6.575 – 6.590 mm
6.44 mm
(0.2589 – 0.2594 in)
(0.2535 in)
EX
6.535 – 6.550 mm
6.40 mm
(0.2573 – 0.2579 in)
(0.2520 in)
Standard
Service limit
IN
0.010 – 0.040 mm
0.11 mm
(0.0004 – 0.0016 in)
(0.004 in)
EX
0.050 – 0.080 mm
0.13 mm
(0.0020 – 0.0031 in)
(0.005 in)
Standard
Service limit
IN/EX
6.600 – 6.615 mm
6.66 mm
(0.2598 – 0.2604 in)
(0.2622 in)
cap.13 EU65is 6500is 07.12.17 5:05 PM ページ13-4
