TOHATSU MFS 4 Service Manual

5
5
Power Unit
1. Special Tools ………………………… 5-2
2. Parts Layout ………………………… 5-3
Engine …………………………………… 5-3
Magneto…………………………………… 5-4
Cylinder & Oil Pan ……………………… 5-6
Cylinder Head & Valve & Cam Shaft … 5-8
Piston & Crank Shaft …………………… 5-10
Recoil Starter …………………………… 5-11
Top Cowl ………………………………… 5-12
3. Inspection Items …………………… 5-13
1)Inspection of Compression Pressure 5-13
2)Inspection of Valve Clearance ……… 5-14
3)Removing Power Unit ………………… 5-16
4)Removal and Disassembly of
Crank Case Head……………………… 5-17
5)Inspection of Crank Case Head……… 5-18
6)Assembly of Crank Case Head ……… 5-18
7)Installation of Crank Case Head …… 5-18
8)Disassembly of Power Unit…………… 5-19
9)Removal of Rocker Arm ……………… 5-22
10) Removing Cylinder Head…………… 5-23
11) Inspection of Rocker Arm and Pivot 5-23
12) Inspection of Push Rod Plate ……… 5-23
13) Inspection of Push Rod …………… 5-23
14) Disassembly and Inspection of
Oil Feed Pump ……………………… 5-23
15) Disassembly of
Cylinder and oil pan ………………… 5-26
16) Disassembly and Inspection of
Breather Chamber ………………… 5-28
17) Inspection of Lifter…………………… 5-28
18) Inspection of Cam Shaft …………… 5-29
19) Inspection of
Piston Outer Diameter ……………… 5-30
20) Inspection of
Cylinder Inner Diameter …………… 5-30
21) Inspection of Piston Clearance …… 5-30
22) Inspection of
Piston Ring Side Clearance………… 5-31
23) Inspection of Piston Rings ………… 5-31
24) Inspection of Piston Pin …………… 5-32
25) Inspection Connecting Rod
Small End Inner Diameter ………… 5-32
26) Inspection of Connecting Rod
Big End Inner Diameter …………… 5-32
27) Inspection of Connecting Rod
Big End Side Clearance …………… 5-33
28) Inspection of Crank Shaft ………… 5-33
29) Disassembly and Inspection of
Oil Pan ……………………………… 5-34
30) Removal of Valves and Springs …… 5-35
31) Inspection of Valve Springs………… 5-35
32) Inspection of Valve ………………… 5-36
33) Inspection of Valve Guide ………… 5-36
34) Inspection of Valve Seat …………… 5-37
35) Correction of Valve Seat …………… 5-38
36) Installation of Valves………………… 5-41
37) Installation of Piston and
Connecting Rod……………………… 5-42
38) Assembly of Cylinder Oil Pan ……… 5-43
39) Installation of Cylinder Head ……… 5-45
40) Installing Flywheel…………………… 5-47
41) Installation of Power Unit…………… 5-50
MFS4-5-6Ech05110425.qxd 11.4.25 1:20 PM  ページ1

TOHATSU MFS 4 Specifications

General

Brand	TOHATSU
Model	MFS 4
Category	Outboard Motor
Language	English