Shibaura ST330, Workshop Manual

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33
➃
Coat the valve seat surface with compound and lap the
contact surface turning the valve.
➄
Check that the valve contact surface is within the
standard value and the contact position is even.
➅ When the cylinder head is replaced with new one,
adjust the seat contact width and seat recess to the
specified values with a seat cutter before lapping.
(4) Valve spring
➀
Check the valve spring visually for damage.
➁
Measure the squareness of the spring using a square on
a surface plate and replace if the service limit is
exceeded.
➂ Check the free length and spring force with a spring
tester and replace if the service limit is exceeded.
(5) Inner face of combustion chamber
Pull out the gasket from the cylinder head. Check and
clean the combustion chamber.
NOTE:
1. Do not remove the insert
from the cylinder head.
116Y
Standard
assembling
value
Service limit
Squareness (mm) 1.2 2
Free length (mm)
35 33.5
Spring force
(when compressed
to 30.4 mm)
72.9 N
｛ 8.1 kgf ｝
68.6 N
｛ 7 kgf ｝
117Y
118Y
Reassembly
Reassemble components in the reverse order to disassembly taking care to the following point.
When assembling the valve spring, retainer and cotter, take deep care not to damage the valve guide seal.
Tighten the glow plug with the tightening torque to 14.7
－ 19.6 N ･ m ｛ 1.5 ～ 2.0 kgf ･ m ｝ .