Tohatsu MFS9.9/15/20E (2020) Parts & Diagrams

OEM and aftermarket replacement parts for Tohatsu MFS9.9/15/20E. Scroll down for exploded parts diagrams (20), specifications, and maintenance reference.

Tohatsu MFS9.9/15/20E (2020) Parts & Diagrams

🔎 Tohatsu MFS9.9/15/20E Reference Library — Exploded parts diagrams (20 diagrams), specifications, common issues, and maintenance checklist.

The Tohatsu MFS9.9/15/20E is a 4-Stroke EFI 2-Cylinder outboard motor. A popular choice for small fishing boats, inflatable RIBs, and sailboat auxiliaries.

Quick Reference Specifications

Specification Value
Engine Type 4-Stroke EFI 2-Cylinder
Horsepower 10 HP
Displacement 333 cc
Bore x Stroke 61.0 x 57.0 mm
Spark Plug (Type & Gap) NGK DCPR6E
Engine Oil Capacity 1.2 L (with filter)
Recommended Engine Oil SAE 10W-30
Gear Case Oil Capacity 320 mL (10.8 fl oz)
Idle Speed (in gear) 900-950 RPM
Full Throttle RPM Range 5400-6100 RPM
Fuel Unleaded Gasoline, 87 Octane min.

Always verify specifications against your owner's manual for your specific serial number range.

Common Issues & Recommended Parts

Below are common maintenance scenarios for the Tohatsu MFS9.9/15/20E:

  • Water Pump / Overheating: If the tell-tale stream is weak or absent, the water pump impeller likely needs replacement. Inspect annually or every 100 hours. → Recommended: Water Pump Impeller Kit
  • Engine Oil / Maintenance Light: 4-stroke engines require regular oil and filter changes. Use marine-grade oil rated for your engine. Change every 100 hours or annually. → Recommended: Oil Filter, Engine Oil
  • Fuel Injector Issues (EFI models): Rough idle or misfires may indicate clogged fuel injectors. Use fuel stabilizer and clean injectors periodically. → Recommended: Fuel Injector, Fuel Filter
  • Gear Case Oil Leak: Check lower unit seals if gear oil appears milky (water contamination). Replace seals and gaskets during lower unit service. → Recommended: Lower Unit Seal Kit, Drain Plug Gaskets
  • Anode Corrosion: Inspect sacrificial anodes regularly, especially in saltwater. Replace when 50% depleted to protect against galvanic corrosion. → Recommended: Zinc/Aluminum Anode Kit

Parts Diagrams & OEM Part Numbers

Expand the sections below to view detailed exploded parts diagrams and find the exact OEM replacement components for your Tohatsu MFS9.9/15/20E.

Fig.01 CYLINDER・CRANK CASE (27 parts) Fig.01 CYLINDER・CRANK CASE
Ref OEM Part # Part Name
1 3RSB01100-0 CYL BLOCK & CRANKCASE ASSY
2 3RS-07636-0 * OIL FILTER BOLT
3 99AA-4-0330 * PIPE
4 345-01111-0 * DOWEL PIN 6-12
5 3H8-01012-1 * CYLINDER HEAD BOLT 8-50
6 9161F9-0630 * BOLT
8 3BJ-07615-0 OIL FILTER
9 3RS-01513-0 HANGER
10 910103-5820 BOLT
11 3RS-01030-0 THERMOSTAT
12 3H6B01031-0 THERMOSTAT CAP
13 346-01032-0 THERMOSTAT CAP GASKET
14 3RT-06869-0 BRACKET
15 3RS-02095-0 BOLT 40mm
17 3RSB02301-0 EXHAUST COVER (OUTER)
18 3RS-02305-0 EXHAUST COVER GASKET
19 3NT-02319-0 BOLT 25mm
20 940203-0600 * WASHER
21 3KY-84398-0 BAND
23 3RS-01303-0 ENGINE BASEMENT GASKET
24 3BJ-61017-1 BOLT 8-P1.25
25 3RS-07710-0 OIL STRAINER ASSY
26 369-84398-1 BAND 202
27 98AH-95-150 HOSE
28 3RS-67143-0 COWL SUPPORT
29 3RT-67143-0 COWL SUPPORT
30 3RS-67144-0 COWL SUPPORT RUBBER
Fig.02 PISTON・CRANK SHAFT (14 parts) Fig.02 PISTON・CRANK SHAFT
Ref OEM Part # Part Name
1 3RS-00040-0 CONNECTING ROD ASSY
2 3RS-00059-0 * CONNECTING ROD BOLT
3 3RS-00030-0 CRANKSHAFT ASSY
4 3RS-07708-0 PLAIN SHAFT BEARING
5 3BJ-00121-0 OIL SEAL 36-50-7
6 3R3-00121-0 OIL SEAL 32-44-9
7 3RS-87131-0 PISTON REPAIR KIT (0.5 O/S)
8 3RS-00004-0 PISTON (0.5 O/S) φ61.5
9 3RS-00021-0 * PISTON PIN
10 3H6-00024-0 * PISTON PIN
11 3RS-87124-0 PISTON RING SET (0.5 O/S) φ61.5
12 3RS-00014-0 * PISTON RING (0.5 O/S)
13 3RS-00015-0 * PISTON RING (0.5 O/S)
14 3RS-00016-0 * PISTON RING-OIL (0.5 O/S)
Fig.03 CYLINDER HEAD・OIL PUMP (44 parts) Fig.03 CYLINDER HEAD・OIL PUMP
Ref OEM Part # Part Name
1 9701-1-1103 SPARK PLUG(DCPR6E)
2 3RTB01000-1 CYLINDER HEAD COMPLETE
3 3RSB01001-0 * CYLINDER HEAD ASSY
4 345-01111-0 ** DOWEL PIN 6-12
5 3H8-07025-0 ** OIL SEAL 18-35-8
6 3RS-07810-0 * CAMSHAFT ASSY
7 3Y2-07935-0 * ROCKER ARM
8 3RS-07935-0 * ROCKER ARM
9 3R0-07238-0 * ADJUSTING SCREW
10 3H8-07237-0 * ADJUSTING NUT
11 3RS-07920-0 * ROCKER ARM SHAFT
12 3AA-07225-0 * ROCKER SHAFT SPRING L=25
12a 3RT-07939-0 * COLLAR
13 3RS-07927-0 * WASHER 13.2-19.5-1
14 3RS-07939-0 * COLLAR
15 3RS-07901-0 * INTAKE VALVE
16 3RS-07902-0 * EXHAUST VALVE
17 3RS-07903-0 * VALVE SPRING
18 3GT-07921-0 * RETAINER
19 3KY-07923-0 * COTTER
20 3RS-07905-0 * VALVE SPRING SEAT
21 3R3-07204-0 * INTAKE VALVE STEM SEAL
22 3R3-07206-0 * EXHAUST VALVE STEM SEAL
22a 3KM-01142-0 * ANODE PLUG ASSY
23 3P0-01143-0 ** ANODE PLUG
24 3T5-10046-0 ** O-RING 1.9-13
25 3P0-60218-0 ** ANODE
26 921503-0530 ** SCREW
27 3RS-07600-0 * OIL PUMP ASSY
28 3RS-07653-0 * OIL PUMP GASKET
29 910103-5635 * BOLT
30 3RS-01005-0 CYLINDER HEAD GASKET
31 3H8-01013-0 CYLINDER HEAD BOLT 8-60
32 9161F9-0640 BOLT
33 940103-0600 WASHER
34 3RSB01020-0 CYLINDER HEAD COVER ASSY
35 3H8-02093-0 * NIPPLE 10-32
36 3RS-07731-0 * BREATHER CHAMBER COVER
37 921521-0408 * SCREW
38 3RS-01024-0 CYLINDER HEAD COVER GASKET
39 910103-5625 BOLT
40 3R0-71015-1 OIL FILLER CAP
41 3R0-07422-0 O-RING 3.1-24.4
42 3KK-02319-0 BOLT 25mm
Fig.04 PULLEY・TIMING BELT (13 parts) Fig.04 PULLEY・TIMING BELT
Ref OEM Part # Part Name
1 3RS-07721-0 OIL LEVEL GAUGE
2 3RS-07720-0 OIL LEVEL GAUGE GUIDE
3 3T5-10162-0 O-RING 1.9-9.8
4 910103-5612 BOLT
5 3BJ-10060-0 DRIVE PULLEY
7 309-00131-0 KEY 10-3.7-3
8 3BJ-10063-0 BELT GUIDE
9 3BJ-10069-0 LOCK WASHER
10 3T5-10068-2 NUT
11 3H8-10062-2 DRIVEN PULLEY
12 3AA-60108-0 PRE-COATED BOLT 6-20
13 3H8-10066-0 WASHER 6.5-19-3.2
14 3RS-10045-0 TIMING BELT
Fig.05 FUEL PUMP (82 parts) Fig.05 FUEL PUMP
Ref OEM Part # Part Name
1 3RS-10200-0 FUEL RAIL ASSY
2 3RS-10201-0 * FUEL RAIL
3 3RS-10300-0 * FUEL INJECTOR ASSY
4 3RS-10323-0 * SEAL RING
5 3T5-10098-0 * VALVE ASSY (PRESSURE CHECK)
6 3T5-10099-0 * CAP
7 3T5-10161-0 * NIPPLE 8-6-13L型
8 3T5-10162-0 * O-RING 1.9-9.8
9 3T5-10169-0 * HOLDING PLATE
10 910103-5612 * BOLT
12 3RS-03952-0 INSULATOR
13 3RS-10100-0 THROTTLE BODY ASSY
14 3RS-10211-0 * ISC VALVE
15 3RS-10214-0 * MAP SENSOR
16 921503-5510 * SCREW
17 921503-5516 * SCREW
18 930103-0600 NUT
19 940103-0600 WASHER
20 3BJ-02011-0 CARBURETOR GASKET
21 3RS-10212-0 HOSE
22 3RS-02409-0 INTAKE SILENCER ASSY
23 910103-0620 BOLT
24 910103-0630 BOLT
28 3RU-02418-0 GASKET
29 3RU-03536-0 RESTRICTOR
30 3RS-10150-0 VAPOR SEPARATOR ASSY
31 3RS-10179-0 * COVER
32 3RS-10180-0 * SEAL
34 3RS-03292-0 * DRAIN SCREW
35 3RS-04116-0 * GASKET
36 3RS-03239-0 * FLOAT VALVE ASSY
37 3RS-03232-0 * FLOAT ARM PIN
38 3RS-03230-0 * FLOAT
39 3RS-04314-0 * GROMMET
40 3RS-04322-0 * FILTER (INLET)
42 3RS-10157-0 * HOLDER
43 3RS-04302-0 * FUEL FEED PUMP
44 3RS-03116-0 * O-RING
45 3RT-03116-0 * O-RING
46 3RS-10095-0 * O-RING
47 3RS-10154-0 * FUEL REGULATOR
48 921503-0408 * SCREW
49 3RS-10172-0 * VST CONNECTOR
50 3RS-03244-0 * CLIP
51 921503-0516 * SCREW
52 3KY-06920-0 RUBBER MOUNT
53 3RS-76079-0 COLLAR
54 3C8-66308-0 WASHER 6-16-1.5
55 910103-0625 BOLT
56 3RS-02168-0 FUEL HOSE W/PROTECTOR
57 3AC-10087-0 CLAMP φ16.8
58 3RS-10185-0 VENT HOSE W/PROTECTOR
59 3RT-10185-0 VENT HOSE W/PROTECTOR
60 3RU-10185-0 VENT HOSE W/PROTECTOR
61 3H8-04000-1 FUEL PUMP ASSY
62 3H8-62415-0 O-RING 3.5-25.7
63 910103-5625 BOLT
64 3RS-04080-0 FUEL HOSE W/PROTECTOR
65 3RT-04080-0 FUEL HOSE W/PROTECTOR
69 3RS-02232-0 FUEL FILTER HOLDER
70 3RS-02239-0 PLATE
71 3RU-67143-0 COWL SUPPORT
73 3T1-06915-0 CLAMP φ10
75 3RT-65212-0 WATER HOSE
76 3RS-65210-0 COOLING HOSE
77 3RT-65210-0 COOLING HOSE
78 3RS-07734-0 BREATHER HOSE W/PROTECTOR
79 3C7-02215-0 CLIP φ12
80 3RS-01138-0 NIPPLE
81 9101E3-5612 BOLT
82 3RU-04080-0 FUEL HOSE W/PROTECTOR
83 3GT-35143-0 CLIP φ9.4
84 369-84398-1 BAND 202
85 3RS-02230-0 FUEL FILTER ASSY
86 3RS-02237-0 * CUP
87 3B7-02234-0 * FILTER
88 3B7-02236-0 * O-RING
89 3RS-02235-0 * O-RING
90 3RS-02253-0 * DRAIN VALVE
91 3RS-02258-0 * SEAL
92 3RS-02229-0 * FLOAT
93 3RS-67144-0 COWL SUPPORT RUBBER
Fig.06 RECOIL STARTER (27 parts) Fig.06 RECOIL STARTER
Ref OEM Part # Part Name
1 3RS-05090-1 RECOIL STARTER ASSY
2 3RS-05105-1 * STARTER CASE
3 3AC-05258-0 * STARTER LOCK CAM SPRING
4 3H8-05004-0 * STARTER SPRING
5 3BJ-05104-0 * REEL
6 3BJ-05135-0 * BUSHING
7 3BJ-05003-0 * RATCHET
8 3BJ-05913-0 * TAPPING SCREW
9 3RS-05913-0 * TAPPING SCREW
10 3RS-05012-0 * RETURN SPRING
11 3H8-05123-1 * RETURN SPRING
12 3RS-05007-0 * FRICTION SPRING
13 3R3-05006-0 * FRICTION PLATE
14 3R3-05013-0 * STARTER ROPE φ5-1800
15 3RS-05019-0 * STARTER HANDLE
16 3AB-05131-0 * ROPE ANCHOR
17 3R3-05252-0 * STARTER LOCK
18 3R3-05216-0 * STARTER LOCK SPRING
19 3RS-05207-0 STARTER LOCK WIRE
20 3RS-67503-0 STARTER SEAL
21 3C8-66308-0 WASHER 6-16-1.5
22 3AL-60108-0 PRE-COATED BOLT 6-20
23 3RS-10320-1 AIR VENT ASSY
24 172-36008-0 GROMMET 13-2
25 3PA-72181-1 CAUTION DECAL (B)
26 3RS-06308-1 BELT COVER
27 3SY-05913-0 TAPPING SCREW
Fig.07 MAGNETO・ELECTRIC PARTS (76 parts) Fig.07 MAGNETO・ELECTRIC PARTS
Ref OEM Part # Part Name
1 3RT-06191-0 FLYWHEEL W/RING GEAR
2 3RT-06023-0 ALTERNATOR ASSY
3 3RS-06071-0 PULSAR COIL
4 910103-5512 BOLT
5 3T5-10131-0 KEY t=4
6 931121-1600 NUT
7 3H8-00133-0 WASHER 16-27-3.2
9 3RS-06008-0 COIL BRACKET
11 3PR-06972-0 CLAMP 6.5-47.5P
12 345-01111-0 DOWEL PIN 6-12
14 3RU-06401-1 ECU ASSY(9.9)
15 3RS-06410-0 ECU HOLDER
16 3RS-06322-0 PLATE
17 3RT-06322-0 PLATE
18 910103-5616 BOLT
19 3BJ-84398-0 BAND 135
21 369-84398-1 BAND 202
23 3RU-76110-0 CORD ASSY
24 3T5-76247-0 * FUSE 20A
26 3RS-06040-0 IGNITION COIL W/R-CAP
27 3AC-06999-0 * PLUG CAP W/RESISTANCE
28 910103-5625 BOLT
29 3H6-07611-1 OIL PRESSURE SWITCH
30 3KY-72510-0 ENGINE TEMP SENSOR
31 3A3-76037-0 CABLE TERMINAL PLUG
32 3V1-06133-0 PROTECTOR φ24-70
33 3BJ-06133-0 PROTECTOR φ10.7-320
34 3SY-06133-0 PROTECTOR φ10.7-210
35 3RT-06899-0 ELECTRIC BRACKET ASSY
36 3RS-06901-0 * BRACKET
37 3H8-76040-0 * STARTER SOLENOID
38 910103-5610 * BOLT
39 3C8-72580-0 * PTT SOLENOID SWITCH (A)
42 3C8-72581-0 * PTT SOLENOID SWITCH (B)
43 930103-0600 * NUT
45 3RS-72582-0 * SOLENOID SWITCH CORD (A)
46 3RS-72583-0 * SOLENOID SWITCH CORD (B)
47 3Y1-76145-0 * TERMINAL CAP 8-13-28
48 3A3-76145-0 * TERMINAL CAP 8-13-28
49b 398-06972-0 CLAMP 6.5-67P
51 3T5-84398-0 * BAND 104
52 3KY-06920-0 RUBBER MOUNT
53 3RS-76079-0 COLLAR
54 3C8-66308-0 WASHER 6-16-1.5
55 910103-0625 BOLT
56 3GF-76010-0 STARTER MOTOR ASSY
57 930203-0600 * NUT
58 3GF-75019-0 * BOLT
59 941303-0600 * SPRING WASHER
60 941321-0500 * SPRING WASHER
61 940221-0500 * WASHER
62 3GF-76015-0 * PINION ASSY
63 3GF-75015-0 * WASHER
64 3GF-75014-0 * BRUSH HOLDER ASSY
65 921521-6408 * SCREW
66 3GF-75017-0 * BUSHING 2
67 3GF-75018-0 * O-RING
68 940103-0600 * WASHER
69 3GF-75016-0 * BUSHING 1
70 3RS-76009-0 STARTER MOTOR BAND
71 3C8-76007-0 DAMPER
72 910103-5825 BOLT
74 3RS-76060-0 RECTIFIER COMPLETE
75 910103-5620 BOLT
76 3RT-76163-0 RECTIFIER BRACKET
78 3BH-76120-0 BATTERY CABLE
80 3BJ-76145-0 TERMINAL CAP 15.5-20-28
81 3Y0-76145-0 TERMINAL CAP 8-18-28
82 3AA-76145-0 TERMINAL CAP 13-13-28
84 910103-5612 BOLT
85 3RS-76141-0 STARTER CABLE
86 3B7-76142-1 GROUND CABLE L=120
87 3RS-76117-0 CLAMP
88 345-06915-0 CLAMP 6.5-14L
91 3SY-76166-0 ASSIST CORD COMPLETE
92 3SZ-76166-0 ASSIST CORD COMPLETE
Fig.08 DRIVE SHAFT HOUSING (25 parts) Fig.08 DRIVE SHAFT HOUSING
Ref OEM Part # Part Name
1 3RTW61020-0 DRIVE SHAFT HOUSING ASSY (S)
2 350-01215-1 OIL SEAL 12.8-25-7
3 3R3-07705-1 DRAIN BOLT 14-14
4 3R3-07406-0 WASHER 14.5-24-1
5 345-01111-0 DOWEL PIN 6-12
7 3AB-01111-0 DOWEL PIN 6-12
8 3RS-65120-0 WATER PIPE (UL)
9 3V1-65206-0 WATER PIPE SEAL (UPPER)
10 3RS-65203-0 LOCK PLATE
11 3V1-65204-0 WATER PIPE AUXILIARY MOUNT 13-2.5
13 3C8-62396-1 GROUND L=210
14 910103-5612 BOLT
15 3RS-72404-0 FLUSHING CONNECTOR CAP
16 3RS-67147-0 SEAL RING
17 3RSW61209-0 IDLE EXHAUST PORT COVER ASSY
18 3RS-62114-0 PLATE
19 9101E3-0512 BOLT
20 3RS-61220-0 IDLE EXHAUST PORT GASKET
21 9101E3-5616 BOLT
22 3RS-67116-0 ENGINE BASEMENT SEAL
23 3RSQ61110-0 EXTENSION HOUSING UL
24 3BJ-60001-0 BOLT 8-31
25 3BJ-60003-0 DRIVE SHAFT BUSHING
26 3V1-64332-0 STOPPER
27 9101E3-5612 BOLT
Fig.09 GEAR CASE (61 parts) Fig.09 GEAR CASE
Ref OEM Part # Part Name
1 3RSW60000-0 GEAR CASE ASSY
2 3BJ-60211-0 * ROLLER BEARING
3 3BJ-60215-0 BALL BEARING 6205HS
4 332-60005-2 PLUG 8-8
5 332-60006-1 GASKET
6 362-60206-1 WATER STRAINER
7 921503-0430 SCREW
8 930403-0400 NYLON NUT 4-P0.7
9 3KY-60218-0 ANODE
10 910103-5620 BOLT
11 930403-0600 NYLON NUT 6-P1.0
12 3BJ-60001-0 BOLT 8-31
13 3RS-60041-0 WATER SEAL RUBBER
14 3RS-60042-0 WATER SEAL PLATE
15 3RSW60100-1 PROPELLER SHAFT HOUSING ASSY
17 3RS-60213-0 * BALL BEARING
18 121-32071-0 * O-RING 2.4-59.6
19 346-65013-0 * OIL SEAL 17-30-9
20 3BJ-60108-0 BOLT
21 3RS-64010-0 BEVEL GEAR ASSY (A)
22 3BJ-64020-0 BEVEL GEAR B
23 346-64027-1 NUT
24 3RS-64030-0 BEVEL GEAR C
25 350-64032-0 WASHER 17.1-22-1.5
26 3RS-64211-1 PROPELLER SHAFT
27 3BJ-64215-0 CLUTCH
28 350-64218-0 PIN φ5-30
29 350-64219-0 SNAP
30 332-64221-0 SPRING
31 3RS-64223-0 PUSH ROD
32 3LD-65021-0 WATER PUMP IMPELLER
33 3RS-65022-0 KEY
34 3RS-65016-1 PUMP CASE (UPPER)
35 3RS-65011-0 PUMP CASE LINER
36 350-65014-0 WATER PIPE SEAL (LOWER)
37 3RS-65002-0 PUMP CASE ASSY (LOWER)
38 332-60223-0 * OIL SEAL 13.8-26-9.5
39 3RS-65020-0 PUMP CASE GASKET (LOWER)
40 3RS-65025-0 WATER PUMP GUIDE PLATE
41 3RS-65029-0 GUIDE PLATE GASKET
42 334-65012-0 DOWEL PIN 4-10
43 3RT-66033-0 STOPPER
44 3RS-66033-0 STOPPER
45 3RS-66021-0 O-RING
46 9101E3-5625 BOLT
47 9101E3-5652 BOLT
48 910103-5512 BOLT
49 346-64084-0 SHIM 35-41.9-0.5
50 3RS-64303-1 DRIVE SHAFT (UL)
51 3RT-60213-0 BALL BEARING
52 3RS-66014-1 CAM ROD (UL)
53 369-66011-0 CLUTCH CAM
54 951407-0310 SPRING PIN 3-10
55 951407-2512 SPRING PIN
56 3Y0B64514-0 PROPELLER ASSY (7)
57 3RS-87326-0 PROPELLER HARDWARE KIT
58 3RS-64231-0 * THRUST HOLDER
59 346-64124-5 * WASHER 12.5-32-2.5
60 346-64121-5 * PROPELLER NUT
61 951503-0322 * SPLIT PIN 3-22
62 3C8-66308-0 WASHER 6-16-1.5
Fig.10 BRACKET (MANUAL) (79 parts) Fig.10 BRACKET (MANUAL)
Ref OEM Part # Part Name
1 3RSW62112-0 CLAMP BRACKET (R)
2 3RSW62113-0 CLAMP BRACKET (L)
3 3H8-72049-0 CO-PILOT DECAL
5 338-60218-2 ANODE
6 910103-5620 BOLT
7 3RS-62117-0 DISTANCE PIECE
9 9401E3-0600 WASHER
10 930103-0600 NUT
11 3AC-62191-0 SWIVEL BRACKET SHAFT ASSY
12 346-62124-1 NYLON NUT 7/8-14
13 349-62126-0 BUSHING
14 346-62127-0 CAP NUT
15 3RS-62123-0 THRUST ROD ASSY
16 369-62122-2 * THRUST ROD SPRING
17 3RTW62309-0 SWIVEL BRACKET ASSY
19 344-67177-1 GREASE FITTING
20 3A3-62396-1 GROUND L=110
21 3AA-61199-0 CARRYING HANDLE
22 3RS-62441-0 FRICTION LEVER
23 3R3-62443-0 WASHER 8.1-20-0.8
24 3B7-63730-0 WASHER 8.5-24-1.5
25 3RS-62445-0 BOLT
26 3V5-62442-0 NYLON NUT 8-P1.25
27 345-66021-0 O-RING 1.9-6.8
28 3RS-62447-0 PLATE
29 9101E3-5612 BOLT
30 3RS-62448-1 WASHER
31 3RS-62449-0 DISC 8.5-38-2
32 3RSW62993-0 TILT STOPPER
33 951403-0540 SPRING PIN
34 350-62437-0 BUSHING 8.2-10-26.5
35 350-62439-1 SETTING PLATE
36 9101E3-5818 BOLT
37 3C8-62421-1 FRICTION SPRING
38 346-62438-0 SETTING PIECE
39 3RS-66311-1 REVERSE LOCK LEVER
42 3AL-05254-0 SHOULDER BOLT 6-8
43 940103-0800 WASHER
44 3AL-05212-0 BUSHING 8.1-20
45 3AA-83719-0 WASHER 8.5-18-1.6
46 3R0-66308-0 WASHER 6-16-1.5
47 3RS-66351-0 REVERSE LOCK (R)
48 3RS-66313-0 REVERSE LOCK ARM
49 3RS-66324-0 REVERSE LOCK SHAFT
50 945303-0600 E-RING d=6
51 3G2-66321-0 REVERSE LOCK ROD
52 951503-0212 SPLIT PIN 2-12
53 3RS-66312-0 REVERSE LOCK LINK
54 3RS-66331-0 REVERSE LOCK SPRING (S)
55 350-66315-0 REVERSE LOCK SPRING
56 3RTW62010-1 STEERING SHAFT ASSY
57 3R3-62417-0 BUSHING 28-31-35
58 3H8-62423-1 THRUST PLATE (UPPER)
59 3H8-62415-0 O-RING 3.5-25.7
60 3RS-61301-0 RUBBER MOUNT (UPPER) 2M
61 9101E3-5830 BOLT
62 3RS-61307-0 BOLT
63 3RS-61333-0 DAMPER (UPPER)
64 3C8-62098-0 NYLON NUT 10-P1.25
65 9402E3-1000 WASHER
66 3RS-61337-0 DAMPER (UPPER)
67 3RS-61336-0 DAMPER (LOWER)
68 3RS-61302-0 RUBBER MOUNT (LOWER)
69 3RSW61401-0 MOUNT BRACKET (R)
70 3RSW61402-0 MOUNT BRACKET (L)
72 3P0-66233-0 WASHER 8.1-16-1.5
73 3RSW62105-1 CLAMP SCREW KIT
74 3RSW62108-0 * CLAMP SCREW ASSY
75 3RS-62106-0 ** CLAMP SCREW
76 3RSW62102-0 ** CLAMP SCREW HANDLE
77 951403-0622 ** SPRING PIN
78 332-62101-1 * CLAMP SCREW PAD
79 945303-0500 * E-RING d=5
80 910103-5612 BOLT
81 3UA-72120-0 RIGGING BOLT SET
82 9101E3-0885 * BOLT
83 9301E3-0800 * NUT
84 9401E3-0800 * WASHER
85 3RS-62424-0 THRUST PLATE (LOWER)
Fig.11 BRACKET (PTT) (69 parts) Fig.11 BRACKET (PTT)
Ref OEM Part # Part Name
1 3H6-60218-0 ANODE
3 398-62396-1 GROUND L=130
4 3V5-62442-0 NYLON NUT 8-P1.25
5 3P0-66233-0 WASHER 8.1-16-1.5
6 3Z0W77211-2 CLAMP BRACKET (PTT-R)
7 3Z0W77212-0 CLAMP BRACKET (PTT-L)
8 3Z0-77115-0 TRIM LOCK PIN
9 910103-5616 BOLT
10 3AA-62116-0 WASHER 22-36-1
11 307-62116-1 WASHER 8.5-28-1
12 3RTW77208-0 SWIVEL BRACKET ASSY
13 3Z0-62476-2 TILT STOPPER
14 369-62433-1 TILT STOPPER GRIP
15 940103-1000 WASHER
16 951403-3516 SPRING PIN 3.5-16
17 3R0-62473-0 TILT STOPPER SPRING
18 353-63207-0 COLLAR 10.2-12-12
19 3Z0-84398-0 BAND 203
20 3KY-77071-0 CYLINDER PIN (UPPER)
22 3R0-77076-0 BUSHING 13-17-19.5 13-17-19.5
23 3Z0-77076-0 BUSHING 13-16-31
24 345-05122-1 WASHER 6.5-23-1.5
25 9101E3-0612 BOLT
26 3Z0-77101-1 CYLINDER PIN (LOWER)
27 910103-0820 BOLT
28 3BJ-72120-0 RIGGING BOLT SET
29 9101E3-0885 * BOLT
30 9301E3-0800 * NUT
31 9401E3-0800 * WASHER
32 3RS-77217-0 CLAMP SCREW KIT
33 3RS-77216-0 * CLAMP SCREW (PTT)
34 332-62101-1 * CLAMP SCREW PAD
35 945303-0500 * E-RING d=5
36 9101E3-5616 BOLT
36a 345-06915-0 CLAMP 6.5-14L
37 910103-5612 BOLT
38 3RSW77151-0 PT ASSY
39 3Z0-77221-0 * CAP ASSY
41 3BA-77175-0 * MANUAL VALVE ASSY
42 3R0-77177-0 ** O-RING 2.4-9.8
44 3R0-77171-0 * C-RING
45 3AC-77173-0 * SEAL WASHER
46 3BA-77450-0 * RELIEF VALVE ASSY
47 3Z0-77179-0 ** O-RING
48 3Z0-77460-0 * VALVE ASSY
49 3R0-77451-0 ** O-RING 1.5-3.5
50 3B7-77169-0 * O-RING
51 3B7-77430-0 * PUMP
52 3B7-77432-1 * BOLT
53 3B7-77431-1 * BOLT
54 3Z0-77431-0 * BOLT
55 3B7-77434-1 * FILTER
56 3E0-77163-0 * COUPLING
57 3R0-77167-0 O-RING 2-62.5
58 3Z1-84398-1 * BAND
59 3V1-64333-0 * PRE-COATED SCREW 5-12
60 3RS-77180-0 * MOTOR ASSY
61 3RS-77192-0 ** MOTOR BRACKET ASSY
62 3Z0-77191-0 *** BREAKER
63 3Z0-77187-0 *** BREAKER HOLDER
64 3Z0-77167-0 *** O-RING
65 3E0-77183-0 *** BRUSH
66 3E0-77184-0 *** BRUSH SPRING
67 921521-5512 *** SCREW
68 3Z0-77186-0 *** BRUSH HOLDER
69 3E0-77193-0 *** OIL SEAL
70 3Z0-77190-0 ** ARMATURE ASSY
71 9215E3-5512 ** SCREW
72 3Z0-77195-0 ** YOKE ASSY
Fig.12 TILLER HANDLE・SHIFT (68 parts) Fig.12 TILLER HANDLE・SHIFT
Ref OEM Part # Part Name
1 3RS-63622-0 THROTTLE DRUM ASSY
3 3RS-66124-0 COLLAR
4 3C8-66308-0 WASHER 6-16-1.5
5 910103-0640 BOLT
6 3RS-63508-0 THROTTLE WIRE BRACKET
8 3RS-63610-0 LINK ROD ASSY (THROTTLE)
9 3RS-63617-0 * THROTTLE ROD
10 3B7-05243-0 * BALL JOINT CONNECTOR
12 3RS-66043-0 GROMMET
13 3GF-66113-1 SHIFT DETENT SPRING
14 3Y1-66117-0 SHIFT DETENT SUPPORTER t=0.8
15 910103-5612 BOLT
16 3RS-66130-0 SHIFT LEVER SHAFT ASSY
17 3RS-66145-0 HOLDER
18 3RT-66145-0 HOLDER
19 910103-5620 BOLT
20 3RS-66215-0 SHIFT ROD (L)
21 3AA-66241-0 SHIFT ROD JOINT
22 930103-0500 NUT
23 3NV-76080-0 NEUTRAL SWITCH
24 3RS-76083-0 NEUTRAL SWITCH ACTUATOR
25 3RS-76081-1 NEUTRAL SWITCH BRACKET
26 910103-5616 BOLT
27 3RTW63003-1 TILLER HANDLE ASSY
28 3RSW63003-1 * TILLER HANDLE ASSY
29 350-67154-0 ** PLASTIC RIVET 6.5
30 3B2-63104-1 ** STUD
31 3R3-63012-0 ** GRIP
32 3V1-63041-0 ** THROTTLE SHAFT
33 3H6-63048-0 ** THROTTLE SHAFT DAMPER
34 3H6-63510-0 ** BUSHING 14-15.8-7
35 921803-0520 ** SCREW
36 3B2-63063-0 ** THROTTLE SHAFT SUPPORT
38 3V1-63035-1 ** FRICTION PIECE
39 3V1-63077-0 ** ADJUSTING NUT
40 3V1-63036-0 ** SPRING
41 910103-0625 ** BOLT
42 3RS-06869-0 ** BRACKET
43 9215E3-0612 ** SCREW
44 3RS-06830-0 ** STOP SWITCH ASSY
44a 353-06821-0 STOP SWITCH LANYARD ASSY
45 3AC-72200-0 ** STOP SWITCH DECAL
46 3AC-72019-0 ** THROTTLE DECAL
47 3RS-72615-0 * PTT SWITCH ASSY
48 3V1-76032-0 * SWITCH BOX
49 9215E3-0516 * SCREW
50 336-06973-0 * CLAMP 6-9.5L
51 9215E3-0512 * SCREW
52 3V1-63102-0 BUSHING
53 3RS-63102-0 BUSHING
54 3RS-63108-0 WASHER
55 3RS-63107-1 COVER
56 9301E3-0600 NUT
57 9402E3-0600 WASHER
58 3RS-63600-0 THROTTLE WIRE
59 3RSW62001-0 STEERING BRACKET
60 344-67177-1 GREASE FITTING
61 3RS-63201-0 BOLT
62 3RT-63201-0 BOLT
63 3WF-67578-0 SHIFT DECAL
64 3RS-66110-0 SHIFT LEVER
65 3H6-63619-1 COLLAR 6.5-10.5-10
66 346-67115-0 WASHER 6.5-21-1
67 9101E3-0620 BOLT
68 3RT-66134-0 SHIFT LEVER ROD
69 951603-0600 SNAP PIN d=6
70 3RS-05259-0 WAVE WASHER
71 3RS-61315-0 WASHER
Fig.13 FRONT PANEL・DRIVE SHAFT HOUSING COVER (32 parts) Fig.13 FRONT PANEL・DRIVE SHAFT HOUSING COVER
Ref OEM Part # Part Name
1 3RSW67010-0 FRONT PANEL
2 3R3-71040-0 PILOT LAMP ASSY
3 394-70260-0 FUEL CONNECTOR (MALE)
4 910103-5616 BOLT
5 345-67117-0 GROMMET 17-2.7
6 3RS-66260-0 GROMMET
7 3R3-66226-0 GROMMET 40-18-3
8 3RS-67512-0 COVER STAY (FRONT)
9 3AL-67592-0 RIVET 4-12.9-2.4
10 3AA-76026-0 MAIN SWITCH ASSY
11 345-67161-0 GROMMET 22-3
12 346-67113-0 MOUNT 8.5-14-2.5
13 3B7-06920-0 RUBBER MOUNT 8.5-14-2.5
14 3RS-05254-0 SHOULDER BOLT
16 346-67115-0 WASHER 6.5-21-1
18 3RSW67003-0 DRIVE SHAFT HOUSING COVER (R)
19 3RSW67004-0 DRIVE SHAFT HOUSING COVER (L)
20 3RTW67004-0 DRIVE SHAFT HOUSING COVER (L)
21 3RS-67485-0 BOLT
22 3RS-63621-0 GROMMET
23 3AA-67120-1 COWL LATCH ASSY
24 910103-0612 BOLT
25 345-05122-1 WASHER 6.5-23-1.5
26 3H6-67572-0 STORAGE DECAL
27 3SY-72615-0 PTT SWITCH ASSY
28 3F3-72616-1 GASKET
29 3SY-76032-0 SWITCH BOX
30 3SY-76035-0 SWITCH BOX GROMMET
31 9215E3-5512 SCREW
32 3RS-67501-0 TOP COWL SEAL
33 3RS-61212-0 GROMMET
34 3H6-70262-0 FUEL CONNECTOR PROTECTOR
Fig.14 REMOTE CONTROL PARTS (26 parts) Fig.14 REMOTE CONTROL PARTS
Ref OEM Part # Part Name
1 3BA-84905-0 DRAG LINK ASSY
2 3E0-84914-0 * SPACER 9.6-19-13
3 3C8-84964-0 * BOLT 3/8-35
4 353-84918-0 * NYLON NUT 3/8-24UNF
5 353-84916-0 * WASHER 9.6-18-2
6 3F3-84908-0 * SEAL RING
7 3RS-83880-0 REMOTE CONTROL FITTING ASSY
8 3RS-83732-0 * GROMMET
9 3RS-83820-0 CABLE CLIP ASSY
10 910103-5616 * BOLT
11 3B7-83715-2 * CABLE JOINT
13 3AA-83719-0 * WASHER 8.5-18-1.6
15 3RS-66122-0 * SHIFT ARM
16 3KY-76079-0 * COLLAR 6.5-10.5-9.3
18 3C8-66308-0 * WASHER 6-16-1.5
19 910103-0625 * BOLT
20 3RS-66134-0 * SHIFT LEVER ROD
21 951603-0800 * SNAP PIN d=8
22 3RS-63751-0 * THROTTLE ARM
23 3RS-63612-0 * THROTTLE OPENER
24 3RS-66124-0 * COLLAR
25 910103-0640 * BOLT
26 3RS-83830-0 * STEERING HOOK PLATE
27 9111E3-1030 * BOLT
28 940103-1000 * WASHER
29 3RV-83914-0 THROTTLE LEVER STOPPER
Fig.15 TOP COWL (7 parts) Fig.15 TOP COWL
Ref OEM Part # Part Name
1 3RSW67645-1 TOP COWL ASSY
2 3RSW67640-0 * TOP COWL SUB-ASSY
6 3WF-87801-0 * DECAL SET (MFS20E)
7 3AC-76190-0 WARNING DECAL
8 3YG-72180-0 CAUTION DECAL (A)
9 3F0-72185-0 CAUTION DECAL
10 3RS-67573-1 SPORT DECAL
Fig.16 FUEL TANK (20 parts) Fig.16 FUEL TANK
Ref OEM Part # Part Name
1 3H6-70200-2 PRIMER BULB ASSY
2 3C7-70220-1 JOINT ASSY (INLET)
3 332-70201-0 CLAMP
4 3C7-70224-1 JOINT ASSY (OUTLET)
5 3GF-70211-1 PRIMER BULB
6 3C7-70217-0 CLAMP
7 98AB-70-700 HOSE
8 98AB-701600 HOSE
9 3GR-70280-0 FUEL CONNECTOR MARK
10 3GF-70281-0 FUEL CONNECTOR
11 3GR-70250-0 FUEL CONNECTOR
12 3UA-70167-0 FUEL TANK ASSY 12L
13 3AC-70052-1 FUEL TANK CAP ASSY
14 3AC-70055-0 RETAINING RING
15 3E0-70270-0 QUICK-CONNECTOR (MALE)
20 3C7-70199-0 O-RING
21 3C7-70113-0 FILTER
22 3RS-70020-0 * FUEL TANK CAP ASSY
22a 3RS-70021-0 ** TANK FILLER CAP GASKET
23 3B2-70155-0 PICK-UP ELBOW ASSY (12L)
Fig.17 COMPONENT PARTS OF REMOTE CONTROL (55 parts) Fig.17 COMPONENT PARTS OF REMOTE CONTROL
Ref OEM Part # Part Name
1 3U2B84340-0 REMOTE CONTROL HEAD ASSY(RC12B)
2 3A3-84365-1 * THROTTLE ARM
3 3A3-84428-0 * THROTTLE FRICTION ARM
4 945303-0600 * E-RING d=6
5 353-84394-0 * WASHER
6 3U2-84427-0 * ADJUSTING SCREW
7 3A3-84381-0 * SHIFT GEAR ASSY
8 3A3-83314-2 * CABLE TERMINAL
9 3A3-84364-2 * DRIVE GEAR
10 930103-0500 * NUT
11 910103-0525 * BOLT
12 3A3-84376-0 * GROMMET
13 3U2B84441-0 * REAR HOUSING
14 3U2B84366-0 * REAR PANEL
15 3U2-84401-0 * NEUTRAL LOCK ARM
16 3A3-84403-0 * NEUTRAL LOCK SPRING
17 3U2-84404-0 * GRIP
18 3U2-84343-0 * CONTROL LEVER
19 3A3-84368-0 * WAVE WASHER
20 3A3-84391-0 * FREE THROTTLE DRUM
21 3A3-84435-0 * BUSHING
22 3A3-84422-0 * THRUST PLATE
23 921603-0512 * SCREW
24 3U2-84339-0 * INSTRUCTION DECAL
25 3A3-84432-0 * BUSHING
26 3U2-84375-0 * SCREW
27 3VK-84375-0 * SCREW
28 3VL-84375-0 * SCREW
29 3A3-84374-0 * SPACER
30 353-84371-0 * WASHER
31 3U2-84371-0 * WASHER
32 930103-0600 * NUT
33 3A3-84383-0 * WASHER
34 3A3-84421-0 * ROLLER
35 3U2-84431-0 * BUSHING
36 940103-0800 * WASHER
37 3U2-84442-0 * BOLT
38 353-84388-0 * DETENT ROLLER
39 3U2B84312-0 * FREE THROTTLE LEVER
40 921503-0406 * SCREW
41 3A3-84423-0 * DETENT RETAINER
42 3A3-84307-0 * DETENT SPRING
43 3A3-84424-0 * FREE THROTTLE ROLLER
44 3A3-84426-0 * ROLLER RETAINER
45 3A3-84425-0 * FREE THROTTLE SPRING
46 3VK-63107-0 * COVER
47 3U2-63506-0 * HOLDER
48 3U2-84917-0 * BOLT
49 3U2-77367-0 * JOINT
50 3U2-06973-0 * CLAMP
51 3U2-72187-0 * CAUTION DECAL(SIGP)
52 3U2B84440-0 * FRONT HOUSING
53 3U2-84452-0 * TILT SWITCH PLUG
54 353-76037-0 * CABLE TERMINAL PLUG
55 3A3-81301-0 TWIN REMOTE CONTROL KIT
Fig.18 COMPONENT PARTS OF REMOTE CONTROL (ELECTRIC PARTS) (16 parts) Fig.18 COMPONENT PARTS OF REMOTE CONTROL (ELECTRIC PARTS)
Ref OEM Part # Part Name
1 3GF-76020-0 MAIN SWITCH ASSY
2 3GF-76219-0 * MAIN SWITCH KEY
3 3GF-76205-0 * MAIN SWITCH KEY COVERING CAP
4 3A3-76115-1 CORD ASSY L=6200
5 353-72546-0 ASSIST CORD (RED) L=200
6 3U2-84331-0 DECAL (LEVER)
7 3U2-84336-0 SHIFT POSITION DECAL
9 3U2-84398-0 BAND
10 3A3-76086-1 NEUTRAL SWITCH (REMOTE CONT)
11 921503-5316 SCREW
12 3U2-72615-0 PTT SWITCH ASSY
13 3C8-76171-0 OVERHEAT BUZZER
14 3A3-06830-0 STOP SWITCH ASSY
15 353-06821-0 * STOP SWITCH LANYARD ASSY
16 3U2-72200-0 STOP SWITCH DECAL
17 3U2-84334-0 REMOTE CONTROL LOGO DECAL
Fig.19 OPTIONAL PARTS・ACCESSORIES (18 parts) Fig.19 OPTIONAL PARTS・ACCESSORIES
Ref OEM Part # Part Name
1 3BJ-72100-0 TOOL KIT
2 3B7-72201-0 SAFETY ROPE φ5-1600
16 361-72539-0 TACHOMETER LEAD WIRE L=6000
17 3RS-06128-1 ALTERNATOR KIT
18 3RT-06023-0 * ALTERNATOR ASSY
19 3RT-76160-0 * RECTIFIER KIT
20 3RS-76060-0 ** RECTIFIER COMPLETE
21 910103-5620 ** BOLT
22 3RT-76163-0 ** RECTIFIER BRACKET
24 910103-5612 ** BOLT
25 3BJ-76161-0 ** EXTENSION CORD L=3000
26 3T5-76247-0 *** FUSE 20A
27 1E0-34093-0 *** CAP
28 3T1-72405-0 HOSE JOINT (WATER-WORKS)
29 3UW-72673-0 SPEEDOMETER KIT (70MPH)
30 3KY-72538-0 SPEEDOMETER LEAD WIRE
31 3KY-72546-0 ASSIST CORD (RED)
32 3A3-72537-1 METER LEAD WIRE
Fig.20 ASSEMBLY・KIT PARTS (13 parts) Fig.20 ASSEMBLY・KIT PARTS
Ref OEM Part # Part Name
1 3RSW87302-2 LOWER UNIT ASSY (L)
2 3RSB87090-2 ENGINE SHORT BLOCK KIT
3 3RS-87121-0 POWER HEAD GASKET SET
4 3RS-87321-0 LOWER UNIT GASKET SET
5 9101E3-5652 * BOLT
6 3RS-65231-0 WATER PUMP KIT (CHROME PLATED)
7 910103-5825 * BOLT
8 9101E3-5612 * BOLT
9 9701-1-1103 * SPARK PLUG(DCPR6E)
10 3RS-07901-0 * INTAKE VALVE
11 3RS-07902-0 * EXHAUST VALVE
12 3PB-72638-0 TACHOMETER KIT
13 3RS-62500-0 STEERING LOCK KIT

100-Hour / Annual Service Checklist

Regular maintenance keeps your Tohatsu MFS9.9/15/20E running reliably season after season. Most of these tasks can be performed with basic tools and the factory service manual.

  1. Replace water pump impeller and inspect wear plate
  2. Change engine oil and oil filter (check drain plug washer)
  3. Replace spark plugs and check ignition timing
  4. Drain and refill lower unit gear oil; inspect for water contamination
  5. Inspect fuel lines, primer bulb, and fuel filter for deterioration
  6. Check and replace sacrificial anodes (zinc or aluminum)
  7. Inspect propeller for damage; check shaft seal and cotter pin
  8. Check valve clearance (refer to service manual for specifications)
  9. Lubricate all grease points (steering, tilt tube, shift linkage)
  10. Inspect control cables and throttle/shift linkage for smooth operation
  • Pro Tip: Always flush the engine with fresh water after saltwater use — even a quick 10-minute flush significantly extends component life.
  • Pro Tip: Use fuel stabilizer in the tank before winter storage, and fog the cylinders to prevent internal corrosion during extended periods of non-use.

Recently Viewed Products