CYLINDER HEAD INSPECTION
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Disassemble the cylinder head (page 9-27).
Use care not to Remove the carbon deposits from the combustion scratch the chamber and exhaust port.
combustion с^еск the spark plug hole and valve areas for
chamber or head cracks
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gasket surface.
Check the cylinder head for warpage with a straight edge and feeler gauge.
SERVICE LIMIT: 0.05 mm (0.002 in)
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EXHAUST VALVE SPRING |
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INTAKE VALVE SPRING
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Check the valve springs for fatigue or damage. Measure the free length of the intake and exhaust valve springs.
SERVICE LIMITS:
IN. 39.7 mm (1.56 in)
EX: 41.9 mm (1.65 in)
Replace the springs if they are shorter than the service limits.
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burns, |
Inspect each valve for out-of-round, scratches or abnormal stem wear.
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Check the valve movement in the guide. Measure and record the valve stem O. D.
STANDARD:
IN: 5.475 - 5.490 mm (0.2156 - 0.2161 in) EX: 4.965 - 4.980 mm (0.1955 - 0.1961 in)
SERVICE LIMIT:
EX: 4.96 mm (0.195 in)
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Take care not to tilt or lean the reamer in the guide while reaming. |
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VALVE GUIDE REAMER |
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07984-2000001 or 07984-200000D (U. S.A. only) 07984-MA60001 or 07984-MA6000D (U. S.A. only) |
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r. |
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Ream the valve guide to remove any carbon buildup before measuring the guide I. D. Insert the reamer from the combustion chamber side of the head and always rotate the reamer clockwise. |
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TOOLS: IN: Valve guide reamer, 5.5 mm EX: Valve guide reamer, 5.0 mm |
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Measure and record each valve guide I. D.
STANDARD:
IN: 5.552 mm (0.2186 in)
EX: 5.052 mm (0.1989 in)
Subtract each valve stem O. D. from the corresponding guide I. D. to obtain the stem-to-guide clearance.
STANDARD:
IN: 0.010 - 0.037 mm (0.0004 - 0.0015 in)
EX: 0.020 - 0.047 mm (0.0008 - 0.0019 in)
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Reface the valve seats whenever the valve guides are replaced Ipage 929). |
If the stem-to-guide clearance exceeds the service limits, determine if a new guide with standard dimensions would bring the clearance within tolerance. If so, replace the guides as necessary and ream to fit.
If the stem-to-guide clearance exceeds the service limits with new guides also, replace the valves and guides.
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VALVE GUIDE REMOVER |
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Mark new valve guides at the proper depth (see specification page 9-30) using a marker. Chill the new valve guides in a freezer for about 1 hour.
Using a torch to Heat the cylinder head to 100 - 150°C (212 - 300°F) heat the cylinder with a hot plate or oven. Do not heat the cylinder head may cause head beyond 160°C (320°F). Use temperature indica - warpage. tor sticks, available from welding supply stores, to be sure the cylinder head is heated to the proper temperature.
Support the cylinder head and drive the valve guides out of the cylinder head from the combustion chamber side.
TOOLS:
IN: Valve guide remover, 5.5 mm 07742-0010100 EX: Valve guide remover, 5.0 mm 07942-MA60000
Adjust the valve guide driver to the valve guide height.
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VALVE GUIDE DRIVER |
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While the cylinder head is still heated, drive new valve guides into the cylinder head from the top of the cylinder (camshaft and rocker arm side).
Check that the valve guides are at the proper depth using a caliper, adjust the height if necessary.
SPECIFIED DEPTH:
IN: 16.1 -16.3 mm (0.63 - 0.64 in)
EX: 17.9-18.1 mm (0.70-0.71 in)
TOOL.
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07743-0020000 not available in U. S.A. |
Valve guide driver
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VALVE GUIDE REAMER |
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Use cutting oil on the reamer during this operation. Take care not to tilt or lean the reamer in the guide while reaming. |
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TOOLS: IN: Valve guide reamer, 5.5 mm EX: Valve guide reamer, 5.0 mm |
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07984-2000001 or 07984-200000D (U. S.A. only) 07984-MA60001 or 07984-MA6000D (U. S.A. only) Clean the cylinder head thoroughly to remove any metal particles after reaming and reface the valve seats (page 9-30). |
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Let the cylinder head cool to room temperature. Ream new valve guides. Insert the reamer from the combustion chamber side of the cylinder head and always rotate the reamer clockwise. |
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