TOHATSU MFS 2 Service Manual

5-22
Power Unit
4st 2/2.5/3.5 2007
17) 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
54.96 mm (2.1638 in)
Measuring Point b :
7mm (0.28 in) upward from the bottom of piston skirt
Functional Limit :
54.90 mm (2.1614 in)
a
b
d
e
D1
D3
D5
D2
D4
D6
a
b
c
18) 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 - 0.060 mm (0.00079 - 0.00236 in)
Functional Limit :
0.150 mm (0.00591 in)
19) 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
55.00mm (2.1654in)
Functional Limit :
55.06mm (2.1677in)
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)
a 5mm (0.2in) d Crank Shaft Direction
b 30mm (1.2in) e Crank Web Direction
c 60mm (2.4in)
MFS2sec05070524.qxd07.5.243:18 PM  ページ22

TOHATSU MFS 2 Specifications

General

Brand	TOHATSU
Model	MFS 2
Category	Engine
Language	English