SELVA MARINE Blue Whale 250 EFI, Service Manual

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6P23H11
5-44
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3. Measure the valve stem diameter
b
.
Replace if out of specification.
4. Measure the valve stem runout. Replace
if above specification.
Checking the valve guide
NOTE:
Before checking the valve guides, make sure
that the valve stem diameter is within specifi-
cation.
1. Measure the valve guide inside diameter
a
.
2. Calculate the valve stem-to-valve guide
clearance as follows. Replace the valve
guide if out of specification.
Valve margin thickness
a
:
Intake:
0.50 – 0.90 mm (0.020 – 0.035 in)
Exhaust:
0.90 – 1.30 mm (0.035 – 0.051 in)
Valve stem diameter
b
:
Intake:
5.477 – 5.492 mm
(0.2156 – 0.2162 in)
Exhaust:
5.464 – 5.479 mm
(0.2151 – 0.2157 in)
Valve stem runout limit:
0.01 mm (0.0004 in)
Valve guide inside diameter
a
:
Intake and exhaust:
5.504 – 5.522 mm
(0.2167 – 0.2174 in)
Valve stem-to-valve guide clearance
= valve guide inside diameter
– valve
stem diameter:
Intake:
0.012 – 0.045 mm
(0.0005 – 0.0018 in)
Exhaust:
0.025 – 0.058 mm
(0.0010 – 0.0023 in)
S69J5770
a
Cylinder head