Shibaura CM284 - Engine Maintenance Standard Table

75
2-5 Engine Maintenance Standard Table
1. J843
* Unit for values without unit in the column of inspection item is mm.
Part Inspection Items
Standard
Dimension
Standard
Assembling Value
Repair Value
Service
Limit
Remarks
Cylinder head
Cylinder compression pressure
MPa {kgf/cm
2
}
More than 2.94
{30}
2.45 {25}
Engine speed
at 200 rpm
Cylinder head tightening torque
N⋅m {kgf⋅m}
98 – 103
{10.0 – 10.5}
Coat
Molycoat
grease.
Distortion of cylinder head bottom surface
(mounting surface)
Less than 0.05 0.12
Valve seat recess (intake/exhaust)
137X
0.85 – 1.15 1.8
Valve sheet
angle 45°
Valve seat contact width
Intake 1.66 – 1.87 2.5
Exhaust 1.66 – 1.73 2.5
Cylinder
block
Bore
φ84 φ84 – 84.019 φ84.2 φ84.2
Distortion on cylinder block top surface Less than 0.05 0.12
Piston
Longer dia. at skirt
φ83.955
φ83.9475 –
83.96
φ83.7
Clearance to cylinder 0.0375 – 0.0715 0.25
At 20°C
Clearance between piston pin hole and pin -0.010 – +0.007 0.02
Piston
pin
Pin outside dia.
φ25
φ24.996 –
25.0
φ24.98
Clearance between rod small end bush and pin.
0.010 –
0.025
0.08 Oil clearance
Piston ring
Clearance between
piston ring groove and
ring
Top ring 0.07 – 0.11
0.25
2nd ring 0.04 – 0.08
Oil ring 0.03 – 0.13 0.25
Ring width
Top ring 2
2nd ring 1.5
Oil ring 4
Piston ring end gap
Top ring 0.20 – 0.35 1.0
2nd ring 0.20 – 0.40 1.0
Oil ring 0.20 – 0.80 1.2