Inspection Of Piston Outer Diameter; Inspection Of Cylinder Inner Diameter; Inspection Of Piston Clearance - TOHATSU MFS 4D Service Manual

4 stroke
Hide thumbs Also See for MFS 4D:
Table of Contents

Advertisement

Power Unit

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
58.96 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
Measure cylinder inner diameters (D1 - D6) at a, b and c in
1.
crankshaft 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.
Cylinder Inner Diameter (D1 - D6) : Standard value
59.00 mm (2.3228 in)
Functional Limit :
59.07 mm (2.3256 in)
Note : Measure at the maximum wear points.
2.
Obtain taper through calculation described below. Replace
cylinder block if taper is over specified value.
Taper Limit :
D1—D5 (Direction d)
D2—D6 (Direction e)
Functional Limit :
0.06 mm (0.0024 in)
3.
Obtain out-of-roundness through calculation described
below. Replace cylinder block if out-of-roundness is over
specified value.
Out-Of-Roundness :
D2—D1 (Measuring Point a)
D6—D5 (Measuring Point c)
Functional Limit :
0.06 mm (0.0024 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.
Piston Clearance :
0.020 - 0.055 mm (0.00079 - 0.00217 in)
Functional Limit :
0.150 mm (0.00591 in)
5-32
a
D2
D4
D6
a 5mm
d Crankshaft Direction
(0.2in)
b 30mm
e Crank Web Direction
(1.2in)
c 60mm
(2.4in)
b
D1
a
b
D3
c
D5
d
e
4st 4/5/6 2020

Advertisement

Table of Contents
loading

This manual is also suitable for:

Mfs 5dMfs 6d

Table of Contents