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G2M0759
1) Remove hydraulic lash adjusters.
2) Compress the valve spring and remove the valve spring
retainer key. Remove each valve and valve spring.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499718000 VALVE SPRING REMOVER
CAUTION:
Mark each valve to prevent confusion.
Use extreme care not to damage the lips of the
intake valve oil seals and exhaust valve oil seals.
G2M0760
C: INSPECTION
1. CYLINDER HEAD
1) Make sure that no crack or other damage exists. In
addition to visual inspection, inspect important areas by
means of red check.
2) Measure the warping of the cylinder head surface that
mates with crankcase by using a straight edge and thick-
ness gauge.
If the warping exceeds 0.05 mm (0.0020 in), regrind the
surface with a surface grinder.
Warping limit:
0.05 mm (0.0020 in)
Grinding limit:
0.3 mm (0.012 in)
Standard height of cylinder head:
127.5 mm (5.02 in)
CAUTION:
Uneven torque for the cylinder head nuts can cause
warping. When reassembling, pay special attention to
the torque so as to tighten evenly.
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2-3bSERVICE PROCEDURE
4. Cylinder Head
Page 426 of 2890
G2M0761
2. VALVE SEAT
Inspect intake and exhaust valve seats, and correct the
contact surfaces with valve seat cutter if they are defective
or when valve guides are replaced.
Valve seat width: W
Intake
Standard
1.0 mm (0.039 in)
Limit
1.7 mm (0.067 in)
Exhaust
Standard
1.5 mm (0.059 in)
Limit
2.2 mm (0.087 in)
3. VALVE GUIDE
1) Check the clearance between valve guide and stem.
The clearance can be checked by measuring the outside
diameter of valve stem and the inside diameter of valve
guide with outside and inside micrometers respectively.
Clearance between the valve guide and valve stem:
Standard
Intake
0.035—0.062 mm (0.0014—0.0024 in)
Exhaust
0.040—0.067 mm (0.0016—0.0026 in)
Limit
0.15 mm (0.0059 in)
Valve guide inner diameter:
6.000—6.015 mm (0.2362—0.2368 in)
Valve stem outer diameter:
Intake
5.950—5.965 mm (0.2343—0.2348 in)
Exhaust
5.950—5.965 mm (0.2343—0.2348 in)
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G2M0762
2) If the clearance between valve guide and stem exceeds
the specification, replace guide as follows:
(1) Place cylinder head on ST1 with the combustion
chamber upward so that valve guides enter the holes
in ST1.
(2) Insert ST2 into valve guide and press it down to
remove valve guide.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499767200 VALVE GUIDE REMOVER
G2M0763
(3) Turn cylinder head upside down and place ST as
shown in the figure.
ST 498267700 VALVE GUIDE ADJUSTER
G2M0764
(4) Before installing new valve guide, make sure that
neither scratches nor damages exist on the inside sur-
face of the valve guide holes in cylinder head.
(5) Put new valve guide, coated with sufficient oil, in
cylinder, and insert ST1 into valve guide. Press in until
the valve guide upper end is flush with the upper sur-
face of ST2.
ST1 499767200 VALVE GUIDE REMOVER
ST2 498267700 VALVE GUIDE ADJUSTER
(6) Check the valve guide protrusion.
Valve guide protrusion: L
12.0—12.4 mm (0.472—0.488 in)
(7) Ream the inside of valve guide with ST. Gently
rotate the reamer clockwise while pressing it lightly into
valve guide, and return it also rotating clockwise. After
reaming, clean valve guide to remove chips.
ST 499767400 VALVE GUIDE REAMER
CAUTION:
Apply engine oil to the reamer when reaming.
If the inner surface of the valve guide is torn, the
edge of the reamer should be slightly ground with an
oil stone.
If the inner surface of the valve guide becomes lus-
trous and the reamer does not chips, use a new reamer
or remedy the reamer.
(8) Recheck the contact condition between valve and
valve seat after replacing valve guide.
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G2M0153
4. INTAKE AND EXHAUST VALVE
1) Inspect the flange and stem of valve, and replace if
damaged, worn, or deformed, or if“H”is less than the
specified limit.
H:
Intake
Standard
1.2 mm (0.047 in)
Limit
0.8 mm (0.031 in)
Exhaust
Standard
1.5 mm (0.059 in)
Limit
0.8 mm (0.031 in)
Valve overall length:
Intake 93.3 mm (3.673 in)
Exhaust 93.6 mm (3.685 in)
2) Put a small amount of grinding compound on the seat
surface and lap the valve and seat surface. Install a new
intake valve oil seal after lapping.
G2M0154
5. VALVE SPRINGS
1) Check valve springs for damage, free length, and ten-
sion. Replace valve spring if it is not to the specifications
presented below.
2) To measure the squareness of the valve spring, stand
the spring on a surface plate and measure its deflection at
the top using a try square.
Valve spring
Free length 39.8 mm (1.567 in)
Tension/spring height228.5—261.8 N
(23.3—26.7 kg, 51.4—58.9 lb)/31.0 mm
(1.220 in)
462.9—531.5 N
(47.2—54.2 kg, 104.1—119.5 lb)/23.2 mm
(0.913 in)
Squareness 2.5°, 1.7 mm (0.067 in)
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G2M0765
6. INTAKE AND EXHAUST VALVE OIL SEAL
Replace oil seal with new one, if lip is damaged or spring
out of place, or when the surfaces of intake valve and valve
seat are reconditioned or intake valve guide is replaced.
1) Place cylinder head on ST1.
2) Press in oil seal to the specified dimension indicated in
the figure by using ST2.
ST1 498267600 CYLINDER HEAD TABLE
ST2 498857100 VALVE OIL SEAL GUIDE
CAUTION:
Apply engine oil to oil seal before force-fitting.
Differentiate between intake valve oil seal and
exhaust valve oil seal by noting their difference in
color.
Color of rubber part:
Intake [Black]
Exhaust [Brown]
Color of spring part:
Intake [Black]
Exhaust [Black]
G2M0766
7. VALVE LASH ADJUSTER
1) Check valve lash adjuster visually.
2) Measure outer diameter of valve lash adjuster.
Outer diameter:
29.959—29.975 mm (1.1795—1.1801 in)
G2M0767
3) Measure inner diameter of bush on cylinder head.
Inner diameter:
29.994—30.016 mm (1.1809—1.1817 in)
CAUTION:
If difference between outer diameter of valve lash
adjuster and inner diameter of bush is over the limit,
replace cylinder head.
Standard:
0.019—0.057 mm (0.0007—0.0022 in)
Limit:
0.100 mm (0.0039 in)
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D: ASSEMBLY
G2M0768
G2M0759
1) Installation of valve spring and valve
(1) Coat stem of each valve with engine oil and insert
valve into valve guide.
CAUTION:
When inserting valve into valve guide, use special care
not to damage the oil seal lip.
(2) Set cylinder head on ST1.
(3) Install valve spring and retainer using ST2.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499718000 VALVE SPRING REMOVER
CAUTION:
Be sure to install the valve springs with their close-
coiled end facing the seat on the cylinder head.
(4) Compress valve spring and fit valve spring retainer
key.
(5) After installing, tap valve spring retainers lightly
with wooden hammer for better seating.
2) Install hydraulic lash adjuster.
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E: INSTALLATION
1. CYLINDER HEAD
B2M0771A
1) Install cylinder head and gaskets on cylinder block.
CAUTION:
Use new cylinder head gaskets.
G2M0771
2) Tighten cylinder head bolts.
(1) Apply a coat of engine oil to washers and bolt
threads.
(2) Tighten all bolts to 29 N⋅m (3.0 kg-m, 22 ft-lb) in
numerical sequence.
Then tighten all bolts to 69 N⋅m (7.0 kg-m, 51 ft-lb) in
numerical sequence.
(3) Back off all bolts by 180°first; back them off by 180°
again.
(4) Tighten bolts
1and2to 34 N⋅m (3.5 kg-m, 25 ft-
lb).
(5) Tighten bolts
3,4,5and6to 15 N⋅m (1.5 kg-m,
11 ft-lb).
(6) Tighten all bolts by 80 to 90°in numerical
sequence.
CAUTION:
Do not tighten bolts more than 90°.
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2-3bSERVICE PROCEDURE
4. Cylinder Head
Page 432 of 2890
(7) Further tighten all bolts by 80 to 90°in numerical
sequence.
CAUTION:
Ensure that the total“re-tightening angle”[steps (6)
and (7) above] do not exceed 180°.
3) Install oil level gauge guide attaching bolt (left side
only).
2. INTAKE MANIFOLD
1) Install camshafts, rocker cover and related parts.
G2M0750
Tightening torque: N⋅m (kg-m, ft-lb)
T1: 10±0.7 (1.0±0.07, 7.2±0.5)
T2: 20±2 (2.0±0.2, 14.5±1.4)
44
2-3bSERVICE PROCEDURE
4. Cylinder Head