TOHATSU MFS 6C, Service Manual, Page: 116 / 260

5-30
Power Unit
4st 4/5/6 2011
a
b
d
e
D1
D3
D5
D2
D4
D6
a
b
c
a
5mm (0.2in)
d
Crank Shaft Direction
b
30mm (1.2in)
e
Crank Web Direction
c
60mm (2.4in)
19) Inspection of Piston Outer Diameter
1. Measure piston outer diameter between points specified.
Replace if it is less than specified value.
Piston Outer Diameter
a
: Standard value
58.960 mm (2.3213 in)
Measuring Point
b
:
7mm (0.28 in) upward from the bottom of piston skirt
Functional Limit :
58.90 mm (2.3189 in)
20) Inspection of Cylinder Inner Diameter
1. Measure cylinder inner diameters (D1 - D6) at
a
,
b
and
c
in
crank shaft directions
d
(D1, D3 and D5 respectively), and in
crank web directions
e
(D2, D4 and D6 respectively). Replace
cylinder block if the inner diameters are over specified value.
2. Obtain taper through calculation described below. Replace
cylinder block if taper is over specified value.
3. Obtain out-of-roundness through calculation described
below. Replace cylinder block if out-of-roundness is over
specified value.
Piston Clearance :
0.020 - 0.055 mm (0.00079 - 0.00217 in)
Functional Limit :
0.150 mm (0.00591 in)
21) Inspection of Piston Clearance
1. If piston clearance is over specified limit, replace cylinder
block, piston and piston rings as a set, or both.
Note : Measure at the maximum wear points.
Cylinder Inner Diameter (D1 - D6) : Standard value
59.00 mm (2.3228 in)
Functional Limit :
59.07 mm (2.3256 in)
Taper Limit :
D1—D5 (Direction
d
)
D2—D6 (Direction
e
)
Functional Limit :
0.06 mm (0.0024 in)
Out-Of-Roundness :
D2—D1 (Measuring Point
a
)
D6—D5 (Measuring Point
c
)
Functional Limit :
0.06 mm (0.0024 in)
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