TOHATSU MFS 2 Service Manual

2-8
Service Data
4st 2/2.5/3.5 2007
5.Maintenance Data
Description
Piston Pin
Ring End Gap
Top Ring
Second Ring
Oil Ring
IN
EX
IN
EX
IN
EX
IN
EX
IN
EX
Valve Spring
Journal Outer Diameter
Engine Block
Compression Pressure
(Reference)
35.0mm (1.38in)
Free Length
5.51mm (0.2169in)
5.51mm (0.2169in)
0.018 - 0.045mm (0.00071 - 0.00177in)
0.025 - 0.052mm (0.00098 - 0.00205in)
Clearance between valve guide and valve stem
Width of contact with valve seat
Valve Guide Inner Diameter
Intake Valve
Exhaust Valve
0.10 - 0.25mm (0.0039 - 0.0098in)
20.010mm (0.78780in)
1.0mm (0.04in)
1.0mm (0.04in)
19.98mm (0.7866in)
Less than 0.05mm (0.0020in) at both ends
0.06 - 0.14mm (0.0024 - 0.0055in)
0.11 - 0.19mm (0.0043 - 0.0075in)
5.47mm (0.2154in)
5.46mm (0.2150in)
Connecting Rod
Crankshaft
Second Ring : 0.30 - 0.45mm (0.0118 - 0.0177in)
Oil Ring : 0.20 - 0.70mm (0.0079 - 0.0276in)
14.01mm (0.5516in)
0.015 - 0.041mm (0.00059 - 0.00161in)
Standard Values
55.00mm (2.1654in)
54.96mm (2.1638in)
0.020 - 0.060mm (0.00079 - 0.00236in)
Top Ring : 0.04 - 0.08mm (0.0016 - 0.0031in)
Small End Inner Diameter
Big End Inner Diameter
Outer Diameter
Big End Side Clearance
Big End Oil Clearance
Top Ring : 0.15 - 0.30mm (0.0059 - 0.0118in)
Measure piston pin hole diameter.
Crank pin outer diameter
Crankshaft roundness : Use V blocks to support crankshaft at
bearings of both ends.
Outer Diameter
・Measure outer diameter at 7mm (0.28in) above lower
end of piston skirt (at right angle to piston pin).
・Piston Clearance
Out-of-roundness
Carbon build up on piston crown and in ring grooves
Piston Ring
Build up of carbon in combustion chamber
Deposits in water jacket
Seizure, cylinder liner damage, or wear
Taper
1.13MPa (164psi) 11.5kgf/㎠
at 500r/min
Item
Second Ring : 0.03 - 0.07mm (0.0012 - 0.0028in)
Oil Ring : 0.05 - 0.15mm (0.0020 - 0.0059in)
Pin clearance to be 0.002 - 0.012mm (0.00008 - 0.00047in).
14.00mm (0.5512in)
24.04mm (0.9464in)
Flywheel side
Lower unit side
11.97mm (0.4713in)
12.97mm (0.5106in)
Cam Shaft Swing
Valve Stem Outer Diameter
Valve Clearance
Wear of bore : Use cylinder gauge to measure inner diameter.
Cam Shaft
Cam Height (Both IN and EX)
Scratch on the sliding surface
Measure side clearance between piston ring and ring groove.
Piston
Cylinder Block/
Cylinder Head
Note : Measurement of ring end
gap : If ring gauge is not
available, use cylinder bore top
or bottom where the wear is
small.
Engine Parts
MFS2sec02070524.qxd07.5.243:12 PM  ページ8

TOHATSU MFS 2 Specifications

General

Brand	TOHATSU
Model	MFS 2
Category	Engine
Language	English