Shibaura SG280E, Workshop Manual

Page: 26 / 111

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3. Cylinder block
1) Inspect for cracks, damage, and deformation in the top
of the block for each cylinder head.
2) Visually inspect the internal diameter of the cylinder
for scratches, rust, and corrosion.
3) Measure the internal diameter of the cylinder at the
top, middle, and bottom in crankshaft direction A as
well as perpendicular direction B.
[Measure within the sliding range of the ring]
Replace the cylinder block if the measurement value
exceeds the usage limit, or if there are scratches or
other damage.
Internal diameter of cylinder block (
φ
)
Assembly standard Usage limit
φ φ φ φ
84.000 to 84.019
φ φ φ φ
84.200 or more
4. Pistons and piston rings
1) Replace pistons that have significant cracking,
striations, or buronout on the periphery.
2) Measure the longest diameter of the piston skirt and
the internal diameter of the cylinder in the thrust
direction. Replace the piston if the measurement
exceeds the required repair level.
[Measure the skirt 10mm from the bottom of the
piston.]
Diameter of bottom of piston skirt ( φ )
Assembly standard Usage limit
83.948 to 83.963 83.700 or less
Deformation in top of cylinder block (mm)
Assembly standard Required repair level
0.05 or less 0.12 or more
Fig.2-5-14
Fig.2-5-15