TOHATSU MFS 4D Service Manual page 8

15) Disassembly of Cylinder and Oil Pan ...... 5-28
16) Disassembly and Inspection of
Breather Chamber .............................. 5-30
17) Inspection of Lifter .............................. 5-30
18) Inspection of Camshaft ........................ 5-31
19) Inspection of Piston Outer Diameter ...... 5-32
20) Inspection of Cylinder Inner Diameter ...... 5-32
21) Inspection of Piston Clearance ............ 5-32
22) Inspection of Piston Ring
Side Clearance ................................. 5-33
23) Inspection of Piston Rings .................. 5-33
24) Inspection of Piston Pin ..................... 5-34
25) nspection Connecting Rod Small End
Inner Diameter ................................. 5-34
26) Inspection of Connecting Rod Big End
Inner Diameter ................................. 5-34
27) Inspection of Connecting Rod Big End
Side Clearance ................................. 5-35
28) Inspection of Crankshaft ..................... 5-35
29) Disassembly and Inspection of Oil Pan ... 5-36
30) Removal of Valves and Springs ............ 5-37
31) Inspection of Valve Springs .................. 5-37
32) Inspection of Valve ........................... 5-38
33) Inspection of Valve Guide .................. 5-38
34) Inspection of Valve Seat ..................... 39
35) Correction of Valve Seat ..................... 5-40
36) Installation of Valves ........................... 5-43
37) Installation of Piston and
Connecting Rod ................................. 5-44
38) Assembly of Cylinder Oil Pan ............... 5-45
39) Installation of Cylinder Head ............... 5-47
40) Installing Flywheel .............................. 5-49
41) Installation of Power Unit ..................... 5-52
6.Lower Unit
1. Special Tools .................................... 6-2
2. Parts Layout .................................... 6-4
Drive Shaft Housing .............................. 6-4
Gear Case (Drive Shaft) • Gear Case
(Propeller Shaft) .................................... 6-6
3. Inspection Item .............................. 6-10
1) Draining Gear Oil .............................. 6-10
2) Removing Propeller ........................... 6-10
3) Removing Lower Unit ........................ 6-11
4) Disassembly of Water Pump ............... 6-11
5) Inspection of Water Pump .................. 6-12
6) Removing Propeller Shaft Housing Ass'y ...... 6-13
7) Disassembly of Propeller Shaft Housing ...... 6-14
8) Inspection of Propeller Shaft Housing ......... 6-14
9) Assembly of Propeller Shaft Housing...... 6-15
10) Removing Drive Shaft ........................ 6-15
11) Disassembly of Propeller Shaft Ass'y ...... 6-16
12) Inspection of Propeller Shaft ............... 6-16
13) Assembly of Propeller Shaft Ass'y ......... 6-16
14) Removing Clutch Cam and Cam Rod ... 6-17
15) Disassembly of Clutch Cam and
Cam Rod .......................................... 6-17
16) Inspection of Clutch Cam and Cam Rod ...... 6-17
17) Assembly of Clutch Cam and Cam Rod ......6-18
18) Removing Pump Case (Lower) ............ 6-18
19) Disassembly of Pump Case (Lower) ...... 6-18
20) Assembly of Pump Case (Lower) ......... 6-18
21) Inspection of Drive Shaft ..................... 6-19
22) Inspection of Pinion (B) Gear and
Forward (A) Gear .............................. 6-19
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23) Disassembly of Gear Case .................. 6-20
24) Inspection of Gear Case ..................... 6-21
25) Assembly of Gear Case ..................... 6-21
26) Installation of Forward Gear and
Pinion Gear (A and B Gears) ............... 6-22
27) Reassembly of Pump Case (Lower) ...... 6-22
28) Installation of Clutch Cam and Cam Rod ...... 6-22
29) Determination of forward (A) gear
backlash .......................................... 6-23
30) Installation of Water Pump .................. 6-25
31) Installation of Propeller Shaft Housing ......... 6-26
32) Filling with Gear Oil ........................... 6-27
33) Installation of Lower Unit ..................... 6-27
7.Bracket
1. Parts Layout .................................... 7-2
Bracket • Reverse Lock ........................... 7-2
Drive Shaft Housing • Shift ..................... 7-4
Bottom Cowl • Tiller Handle ..................... 7-6
Top Cowl ............................................. 7-10
2. Disassembling and
Assembling Procedure ........................... 7-11
1) Removal and Inspection of
Drive Shaft Housing ........................... 7-11
2) Removal and Inspection of Clamp
Bracket .......................................... 7-13
3 ) Installation of Clamp Bracket and
Drive Shaft Housing ........................... 7-14
4) Removal, Inspection and Installation of
Water Pipe ....................................... 7-16
5) Remove, Inspection and Installation of
Tiller Handle .................................... 7-17
6) Adjustment of Throttle Cable ............... 7-20
8.Electrical System
1. Special Tools .................................... 8-2
2. Parts Layout .................................... 8-4
Magneto ............................................. 8-4
3. Ignition System and
Ignition Control System .................. 8-6
1) Inspection of Ignition Spark .................. 8-6
2) Inspection of Plug Cap ........................ 8-7
4) Inspection of Stop Switch ..................... 8-9
5) Inspection of Oil Pressure Switch ......... 8-9
6) Inspection of Rectifier ........................ 8-10
7) Inspection of Lighting Coil .................. 8-10
9.Troubleshooting
1. Troubleshooting List ........................ 9-2
2. Power Unit ....................................... 9-3
1 Engine will not start or is a little hard to start.
(Recoil starter operates normally.) ............ 9-3
2 Engine starts but stalls soon. ............... 9-5
Fuel System .................................... 9-5
Ignition System ................................. 9-6
Intake • Compression Pressure ............ 9-7
3 Idle engine speed will not stabilize. ...... 9-8
4 Rough acceleration. ........................... 9-9
5 Gear shifting cannot be made
normally. .......................................... 9-10
10.Wiring Diagram
4st 4/5/6 2020