Page 1 S E R V I C E M A N U A L 4 STROKE MFS 25D MFS 30D Models OB No.003-21077-0BB2 ｜ 07-22 NB...
Page 3 Introduction Before reading this manual This service manual provides information that is needed for inspection, service and repair of applicable outboard motors. For information about operation of the products that are not described in this document, refer to the owners manual. For our customers' safe and dependable use of the product for long term, it is essential to maintain the performance and quality of the outboard.
Page 4 About this manual Composition and use of this manual This service manual is designed so that service persons are able to perform repairs correctly. Understand the following matters well for efficient service and repair. 1 Each chapter begins with the introduction of special tools that are used for the work described. 2 Parts that are serviced in each chapter and their details are presented by using a component composition diagram.
Page 5 This manual uses SI unit system (International System of Units) for pressure, force (load), torque and stress. This manual newly adopts the international unit construction system (SI unit system) followed by the conventional imperial and metric systems enclosed by ( ) and [ ] as described below. Example : <Pressure>...
Page 6 Description of Pictograph The following symbols represent the contents of individual chapters. Service Inspections and Service Data Fuel System Information Adjustments (Fuel Injection) Electrical Power Unit Lower Unit Bracket System Wiring r/min Troubleshooting Rigging Diagrams The following symbols indicate items needed for the service. Lubrication Tightening Special Tool...
Page 7 1. Service Information 9) Replacement of Gear Oil ……………… 3-11 10) Inspection of Gear Case (for leakage) … 3-12 1. Identification (Engine Serial Number) … 1-2 11) Inspection of Timing Belt ………………… 3-12 2. Securing of Work Safety ……………… 1-2 12) Replacement of Timing Belt ……………...
Page 8 (6) Warning Buzzer and Lamp (LED), 12) Removal of Air Intake System & Fuel System ……………………………… 5-43 and Control of Engine Revolution Speed …………………………………… 4-24 13) Removal of Electrical System Parts …… 5-46 1) Location of Warning Buzzer and 14) Removal of Cylinder Head Assy ……… 5-49 Lamp (LED) ………………………………...
Page 9 6) Inspection of Water Pipe ………………… 6-13 12) Disassembly of Clamp Bracket 7) Disassembly of Water Pump Case (Lower) … 6-14 (Manual Tilt Model) ……………………… 7-38 8) Assembly of Water Pump Case (Lower) … 6-14 13) Installation of Clamp Bracket 9) Disassembly of Cam Rod ………………...
Page 10 6) Inspection of the Brush ………………… 8-31 2) Installation of the Battery ……………… 10-17 7) Starter Motor Operation Test …………… 8-32 3) Wiring Diagram of the 7. The Charging System (Except for MF) … 8-32 Remote Controller and Meters ………… 10-18 1) Inspection of the Charge Coil ……………...
Page 11 INDEX Service Information Service Data Maintenance Fuel System (Fuel Injection) Power Unit Lower Unit Bracket Electrical System Troubleshooting r/ in Rigging Wiring Diagram 4st 25/30 2022...
Page 12 4st 25/30 2022...
Page 13: Table Of Contents
Service Information 1. Identification (Engine Serial Number) … 1-2 3) Engine Oil ………………………………… 1-10 2. Securing of Work Safety ……………… 1-2 4) Gear Oil …………………………………… 1-10 1) Fire Prevention …………………………… 1-2 5) Fuel Line ………………………………… 1-10 2) Ventilation ………………………………… 1-2 6) Rigging ……………………………………...
Page 14: Identification (Engine Serial Number)
Service Information 1. Identification (Engine Serial Number) The engine serial number is stamped on the swivel bracket of the outboard motor body. 1 Model Name 2 Serial Number A Manual Tilt Model B Gas Assist Model, Power Tilt Model 2. Ensuring Work Safety 1) Fire Prevention Gasoline is a hazardous material and very flammable.
Page 15: Genuine Parts
4) Genuine Parts U s e p a r t s a n d / o r c h e m i c a l s t h a t a r e g e n u i n e o r recommended.
Page 16: Cautions In Disassembling And Assembling Components
Service Information 7) Cautions in disassembling and assembling components Install the outboard motor securely to a dedicated stand. Take special care not to scratch the painted surfaces or mating surfaces of the cylinder and crankcase. Replace parts that cannot be reused such as packings, gaskets, O-rings, oil seals, spring pins or split pins with new ones after disassembly.
Page 17: Tools And Instruments
3. Tools and Instruments 1) Test Propeller MFS25 MFS30 Part No. 3VS-64110-0 3VS-64110-0 Outer Diameter a 223 mm (8.78 in) 223 mm (8.78 in) Width b 16 mm (0.63 in) 16 mm (0.63 in) Fully Open Revolution Speed 5500 min (rpm) 6000 min (rpm)
Page 18: Special Tools
Service Information 3) Special Tools Bevel Gear B Nut Wrench Bevel Gear B Nut Socket Shimming Gauge Thickness Gauge P/N. 346-72231-0 P/N. 346-72232-0 P/N. 346-72250-0 P/N. 353-72251-1 Bevel gear B Removal/installation of pinion nut (B gear nut) Measurement of gaps height adjustment Piston Slider Spring Pin Tool A...
Page 19 ø34.5 x ø17.5 ø27.5 x ø15.5 ø29.5 x ø16.5 Oil Seal Attachment Oil Seal Attachment 2 Oil Seal Attachment 3 Universal Puller Plate P/N. 3AC-99820-0 P/N. 3AD-99820-0 P/N. 3AG-99820-0 P/N. 3AC-99750-0 Installation of oil seal on Installation of oil seal of Installation of oil seal of Removal of bearing cylinder head...
Page 20 Service Information Crank Shaft Holder Flywheel Puller Kit Roller Bearing Press Kit P/N. 3BJ-72815-0 P/N. 3T1-72211-4 P/N. 3AC-72900-3 Holding crankshaft Installation/removal of Removal/installation of flywheel Tightening of pulley nut gear case roller bearing Valve Spring Compressor Attachment P/N. 3AB-99076-0 Installation/removal of valve spring 4st 25/30 2022...
Page 21: Pre-Delivery Inspection
4. Pre-delivery Inspection 1) Steering Handle A Check installations for clattering and play B Adjust steering friction C Check throttle grip for movement (full open/full close) Adjust throttle friction 2) Gear Shift Check that gear shifts from neutral (N) to forward (F) and reverse (R) smoothly.
Page 22: Engine Oil
Service Information 3) Engine Oil CAUTION Engine oil is removed before shipment to prevent leakage. Fill the engine with engine oil. 4 Stroke Engine Oil: 1500 mL (1.6 US.qt) [without oil filter replacement] a Upper Limit b Lower Limit 1700 mL (1.8 US.qt.) [oil filter replaced] Use oil level gauge to check oil quantity.
Page 23: Inspection Of Ptt Unit (Eft, Eht, Ept)
7) Inspection of PT Unit (EFT, EHT, EPT) Operate the PT switch to check that the outboard motor tilts up/down smoothly. Operate the PT switch to check that no abnormal noise is made when tilting the outboard motor up/down. Tilt up the outboard motor and steer fully to the right and left to check that the cables and hoses do not interfere with each other and with any part of the hull.
Page 24: Stop Switch
Service Information 10) Inspection of Starting Switch and Stop Switch Press start switch 1 or turn main switch key 2 to the START position a to check that the engine starts. Turn the main switch key to the OFF position b to check that the engine stops.
Page 25 Press the stop switch 3 hard or pull out the lock 4 from the stop switch to check that the engine stops. A Basic Tiller Handle Model B Multi-Function Tiller Handle Model C Remote Control Model 1-13 4st 25/30 2022...
Page 26: Cooling Water Check Port
Select a propeller that is best-suited to type of boat and application. Fully Open Operating RPM Range: MFS 25D: 5000 to 6000 min (rpm) MFS 30D: 5500 to 6500 min (rpm) 1-14...
Page 27: Trim Tab
Propeller List (No. of Blades x Pitch x Diameter) Propeller Mark Part No. F 8 1/4 3 x 8 x 10.2 3 x 210 x 260 346B64106-5 9.9 x 9 3 x 9 x 9.7 3 x 229 x 247 3R0B64518-1 9.9 x 10 3 x 10 x 9.7...
Page 28: Break-In Operation
Service Information 5. Break-in Operation B r e a k - i n o p e r a t i o n i s n e e d e d f o r t h e p u r p o s e o f smoothening the sliding surfaces between components such as pistons and cylinder, piston rings, piston pins, crankshaft, connecting rods, and intake and exhaust...
Page 29: Checks After Test Run
Run at 3,000 min (rpm) or half of the WOT for an initial 2 hours, then at 4,000 min (rpm) or 3/4 of the WOT for 1 hour. Check that the outboard motor is not tilted up and that water does not infiltrate the boat when the gear is shifted to the Reverse (R) position.
Page 30 Service Information 1-18 4st 25/30 2022...
Page 31 Service Data 1. Outline Dimensions …………………… 2-2 4. Cooling Water System Diagram …… 2-11 1) Engine Dimensions ……………………… 2-2 5. Specifications …………………………… 2-12 2) Transom Bolts …………………………… 2-8 6. Maintenance Data ……………………… 2-16 2. Fuel Injection System ………………… 2-9 7. Tightening Torque Data ……………… 2-24 1) ECU Fuel Feed System …………………...
Page 32: Outline Dimensions
Service Data 1. Outline Dimensions 1) Engine Dimensions Basic Tiller Handle Model 4st 25/30 2022...
Page 33 MF/EF (Manual Tilt Model) EFG (Gas Assist Model) EFT (Power Tilt Model) Item Type Unit mm/in 22.50 22.50 22.50 mm/in 13.30 13.30 13.30 deg. mm/in 30.05 30.25 30.60 mm/in 34.35 34.35 35.00 mm/in 38.70 38.50 1001 39.40 mm/in 22.75 21.85 21.85 mm/in 21.05...
Page 34 Service Data Multi-Function Tiller Handle Model 4st 25/30 2022...
Page 35 EH (Manual Tilt Model) EHT (Power Tilt Model) Item Type Unit mm/in 26.55 26.55 mm/in 18.85 18.85 mm/in 13.30 13.30 deg. mm/in 30.05 30.60 mm/in 34.35 35.00 mm/in 38.70 1001 39.40 mm/in 32.65 31.75 mm/in 21.05 22.00 mm/in 16.25 15.60 mm/in 9.25 8.35...
Page 36 Service Data Remote Control Model 4st 25/30 2022...
Page 37 EP (Manual Tilt Model) EPT (Power Tilt Model) Item Type Unit mm/in 13.30 13.30 mm/in 13.30 13.30 deg. mm/in 30.05 30.60 mm/in 34.35 35.00 mm/in 38.70 1001 39.40 mm/in 15.80 15.60 mm/in 21.05 22.00 mm/in 7.75 6.80 mm/in 2.95 2.00 mm/in 16.75 16.75...
Page 38: Transom Bolts
Service Data 2) Transom Bolts Manual Tilt Model 231 mm (9.10 in) Gas Assist/Power Tilt Model 351 mm (13.80 in) 327 mm (12.85 in) 251 mm (9.90 in) 4st 25/30 2022...
Page 39: Fuel Injection System
2. Fuel Injection System 1) ECU Fuel Feed System The ECU uses various sensors to precisely control the injected fuel amount (time) and ignition timing. Fuel Feed Pump Alternator (FFP) (Exciter Coil) Fuel Control Pulser Coil Fuel Injector (Crank Position Sensor) Idle MAP(Intake pressure) (Idle Speed Control Valve) Air Control Sensor Electric Ignition Control MAT(Intake air...
Page 40: Engine Lubrication System Diagram
Service Data 3. Engine Lubrication System Diagram Oil Filter Main Gallery 2-10 4st 25/30 2022...
Page 41: Cooling Water System Diagram
4. Cooling Water System Diagram Thermostat Cylinder Head Cylinder Sub-cooling Main Cooling Water Intake Water Intake Vapor Separator Cooling Water Pump Cooling Water Pipe Lower part of cylinder Cooling (Water supply Water Vapor Separator passages Check Port in the drive shaft housing) Cooling Idle Port Water Pipe Idle Port Drive Shaft Housing Cylinder Cylinder Head Sub-cooling Water Intake Cooling Water Pump Thermostat Main Cooling Water Intake Lower part of cylinder Exhaust Gas &...
Page 42: Specifications
Service Data 5. Specifications Model MFS 25D/30D Item Unit Basic Tiller Multi-Function Tiller Remote Control Model Handle Model Handle Model Dimensions (approx.) Overall Length mm (in) 1113 (43.80) 1360 (53.55) 732 (28.80) Overall Width mm (in) 401 (15.80) 389 (15.30) 389 (15.30)
Page 43 Model MFS 25D/30D Item Unit Basic Tiller Multi-Function Tiller Remote Control Model Handle Model Handle Model Fuel & Oil Type of Fuel Unleaded Regular Gasoline: R+M/2: 87 or higher / RON: 91 or higher Fuel Tank Capacity L (US gal.) 25 (6.6)
Page 44 Service Data Model MFS 25D/30D Item Unit Basic Tiller Multi-Function Tiller Remote Control Model Handle Model Handle Model Warning System Warning System Warning buzzer sounds (for 1 second only), and lamp is lit (for 1 second). Operation Check Engine temp.
Page 45 2-15 4st 25/30 2022...
Page 46: Maintenance Data
Service Data 6. Maintenance Data Description Item Standard Value Compression pressure (reference value) Note) After warming up, remove all the spark With Decompression: 0.50 MPa Engine plugs and injector connectors, then Without Decompression: 1.40 MPa take measurements with the throttle fully opened.
Page 47 Functional Limit Action To Be Taken Check if rotating parts, sliding parts and sealing parts cause compression leakage. Adjust to specified range Replace if less than specified limit IN: 0.05 mm (0.0020 in) Replace if more than specified limit EX: 0.03 mm (0.0012 in) Replace if more than specified limit IN: 0.070 mm (0.0028 in) Replace if more than specified limit...
Page 48 Service Data Description Item Standard Value Cylinder Liner Inner Diameter Use a cylinder gauge etc. to measure the inner diameter Seizure, Cylinder Liner Damage or Wear Cylinder Block Distortion or Damage on Mating Surface Distortion: 0.05 mm (0.002 in) or less Deposition in Water Jacket Small End Inner Diameter Connecting...
Page 49 Functional Limit Action To Be Taken Replace if more than specified limit • Difference of 0.06 mm (0.0024 in) between the most worn out Replace if the difference between the most worn out area and least area and least worn out area of the liner inner diameter worn out area of the liner inner diameter is above the specified (Roundness 0.06) value.
Page 50 Service Data Description Item Standard Value Plug Type DCPR6E (NGK) Spark Plug Spark Gap 0.8 - 0.9 mm (0.030 - 0.035 in) Primary Coil Resistance Ignition Coil Secondary Coil Resistance Alternator (MAX) 12V–210W 1000 r/min, 14 V, 6 A or more Magneto Power Generation Performance (Alternator)
Page 51 Functional Limit Action To Be Taken Clean and remove the carbon stains or damage Replace if the electrode is worn out significantly Spark gap 1.2 mm (0.045 in) Replace if out of standard value Replace if out of standard value Replace if out of standard value Replace if out of standard value Replace if out of standard value...
Page 52 Service Data Description Item Standard Value Piston Diameter Piston Rod Diameter Cylinder Stroke 140 mm (5.5118 in) Shock Absorber Valve Opening Pressure 14.4 - 20.5 MPa Rated Voltage 12 V (DC) Continuous Run 60 sec PT Solenoid (UP/DN) Excitation Current 4 A or less Exciter Coil Resistance Valve Operation Starting Temperature...
Page 53 Functional Limit Action To Be Taken Any opening under ambient temperature Replace if out of specified range Less than 3 mm (0.1181 in) Replace if less than specified limit Wear, crack or damage on tips and upper and lower surface lips Replace pump case liner and guide plate as a set.
Page 54: Tightening Torque Data
Service Data 7. Tightening Torque Data Tightening Torque Type of Fastened Components Wrench A Screw B x Pitch Fastener N · m lb · ft kgf · m First Tightening Torque M8 x 1.25 Second Tightening Torque Cylinder Head Mounting Bolt Bolt (Cylinder Block - Cylinder Head) First Tightening Torque...
Page 55 Tightening Torque Type of Fastened Components Wrench A Screw B x Pitch Fastener N · m lb · ft kgf · m 7/8-14 Clamp Bracket Tilt Tube Nylon Nut UNF-2B PT Assy Manual Valve Special 0.18 Bevel Gear B Nut M12 x 1.0 Propeller Nut M12 x 1.5...
Page 56: Sealant Application Locations
Service Data 8. Sealant Application Locations Three Three Three Three Three Three Three Loctite Loctite Tosseal Bond Bond Bond Bond Bond Bond Bond Location of Use 1342 1327 1322 1373B 1377N 1401 5910 1207B 381 (271) Cam Shaft Oil Seal (Cam Shaft) Driven Pulley Bolt Rocker Arm Lifter...
Page 57 Remarks Three Shinetsu Three Loctite Konishi Konishi Emulsion Center Chuo Yuka Sumico Bond Silicone Bond Research Molytone 1741 G103 P-80 KS-64 Grease 5211 (7782) #101 No.1 Cam Unit Bearing Outer Surface, Press Fit Thread Bearing, Roller, Sliding Part Entire Surface Entire Surface Outer Face Shaft, Stem Head...
Page 58 Service Data Three Three Three Three Three Three Three Loctite Loctite Tosseal Bond Bond Bond Bond Bond Bond Bond Location of Use 1342 1327 1322 1373B 1377N 1401 5910 1207B 381 (271) Bolt (Holding Plate) O-Ring (Injector) Fuel Rail Seal Ring Valve Map Sensor Intake Manifold...
Page 59 Remarks Three Shinetsu Three Loctite Konishi Konishi Emulsion Center Chuo Yuka Sumico Bond Silicone Bond Research Molytone 1741 G103 P-80 KS-64 Grease 5211 (7782) #101 No.1 Entire Surface Entire Surface Entire Surface Thread O-Ring High Tension Cord Plug Cap End Taper screw section (side to mount the block) Terminals, HEX section Terminals...
Page 60 Service Data Three Three Three Three Three Three Three Loctite Loctite Tosseal Bond Bond Bond Bond Bond Bond Bond Location of Use 1342 1327 1322 1373B 1377N 1401 5910 1207B 381 (271) Propeller Shaft Clutch Ball Propeller Shaft Snap Push Rod Spring O-ring Oil Seal...
Page 61 Remarks Three Shinetsu Three Loctite Konishi Konishi Emulsion Center Chuo Yuka Sumico Bond Silicone Bond Research Molytone 1741 G103 P-80 KS-64 Grease 5211 (7782) #101 No.1 Propeller Side Spline Range from clutch side tip to pressure-welded section Spline Section Entire Surface Entire Surface Entire Surface Entire Surface...
Page 62 Service Data Three Three Three Three Three Three Three Loctite Loctite Tosseal Bond Bond Bond Bond Bond Bond Bond Location of Use 1342 1327 1322 1373B 1377N 1401 5910 1207B 381 (271) Bushing (Steering Shaft) Bushing (Swivel Shaft) Bushing (Cylinder Pin Upper, Lower) Bracket O-Ring (Steering Bracket) Swivel Bracket Shaft...
Page 63 Remarks Three Shinetsu Three Loctite Konishi Konishi Emulsion Center Chuo Yuka Sumico Bond Silicone Bond Research Molytone 1741 G103 P-80 KS-64 Grease 5211 (7782) #101 No.1 Outer Face, Inner Face Outer Face, Inner Face Outer Face, Inner Face Entire Surface Sliding Face Sliding Face Sliding Face...
Page 64 Service Data 2-34 4st 25/30 2022...
Page 65 Maintenance 1. Special Tools ……………………………… 3-2 17) Adjustment of Shift • Throttle Cable 2. Inspection Schedule …………………… 3-3 (Multi-Function Tiller Handle Model) …… 3-22 3. Inspection Items ………………………… 3-4 18) Adjustment of Shift • Throttle Cable 1) Inspection of Top Cowl ………………… 3-4 (Remote Control Model) …………………...
Page 66 Maintenance 1. Special Tools Oil Filter Wrench Spring Pin Tool A Flywheel Puller Kit P/N. 3AC-99090-0 P/N. 345-72227-0 P/N. 3T1-72211-4 Removal/installation of Removal of spring pin oil filter (ø3.0) Thickness Gauge Compression Gauge Valve Clearance Driver Torque Wrench P/N. 353-72251-1 P/N.
Page 67: Inspection Schedule
2. Inspection Schedule Inspection intervals First Every Every Every Every Inspection parts Inspection procedure Remarks 20 hours 50 hours 100 hours 200 hours 400 hours or 1 month or 3 months or 6 months or 1 year or 2 years Check, Clean or Replace if Fuel Filter Necessary...
Page 68: Inspection Items
Maintenance 3. Inspection Items 1) Inspection of Top Cowl Push the top cowl with both hands to check the rattling and tightening condition. 2) Fuel System Inspection of Fuel Hose C h e c k t h e f u e l s y s t e m p i p i n g f o r f u e l l e a k , d i r t , deterioration and damage, and replace or repair parts if necessary.
Page 69: Inspection Of Fuel Tank
3) Inspection of Fuel Tank Remove the four screws from the fuel tank 1, remove the fuel pick up elbow 2, and clean the filter 3. Remove dirt and water from the fuel tank if any. 2 Fuel Pick Up Elbow 3 Filter 4) Inspection of Fuel Filter CAUTION...
Page 70: Replacement Of Engine Oil
Oil Level 1 Oil Level Gauge a Upper Limit b Lower Limit Oil Specification Recommended Engine Oil: Tohatsu 4-Stroke Engine Oil 10W – 40 Recommended Engine Oil Grade: API: SH, SJ, SL 10W – 30 SAE: 10W-30, 10W-40 Quantity of Engine Oil: (When oil filter is replaced) : 1.7 L (1.8 US qt.)
Page 71: Replacement Of Oil Filter
• Apply engine oil on the sealing areas of the engine oil drain bolt. • Use a new gasket. Engine Oil Drain Bolt: 24 N · m (18 lb · ft) [2.4 kgf · m] 5. Pour the specified amount of new engine oil into the oil inlet 3 while checking the amount using the oil level gauge 4.
Page 72 Maintenance Pour engine oil into the oil inlet 3. Recommended Engine Oil: Tohatsu 4-Stroke Engine Oil Recommended Engine Oil Grade: API: SH, SJ, SL SAE: 10W-30, 10W-40 Quantity of Engine Oil: (When oil filter is replaced) : 1.7 L (1.8 US qt.) (When oil filter is not replaced): 1.5 L (1.6 US qt.)
Page 73: Inspection Of Gear Oil Quantity
Do not reuse. Replenish the gear oil to the specified level if it is insufficient. Recommended Gear Oil: Tohatsu Gear Oil Recommended Gear Oil Grade: API: GL-5 SAE: #80 - 90 If the shortage is large, replenish through the lower oil plug hole.
Page 74 Maintenance Remove the lower unit installation bolts and pull down the lower unit assembly 3 to remove it. Remove the pump upper case 4. Remove the impeller 5 and check it. Check the pump case (upper) to see if there is any deformation.
Page 75: Replacement Of Gear Oil
Recommended Gear Oil: Tohatsu Gear Oil Recommended Gear Oil Grade: API: GL-5 SAE: #80 - 90 Quantity of Gear Oil: 460 ml (16 US fl.oz.)
Page 76: Inspection Of Gear Case (For Leakage)
Maintenance 10) Inspection of Gear Case (for leakage) Drain the gear oil. Remove the upper oil plug 1 and connect a commercially available leakage tester to the hole. Apply the specified pressure to the gear case, and check if the pressure can be held for 10 seconds. CAUTION Do not subject the gear case to a pressure over the specified value.
Page 77: Replacement Of Timing Belt
Check the timing belt inner and outer surfaces for cracks, damage, and wear while rotating the flywheel clockwise with your hands. Replace if necessary. Bend limit a: Push the belt center as shown. Replace the belt if it deflects by 10 mm or more. 12) Replacement of Timing Belt Remove the recoil starter and belt cover.
Page 78 Maintenance Using the flywheel puller kit 2 as shown in the figure on the right, remove the flywheel 3 and key. Screw the puller onto the end of the crankshaft until the flywheel is disengaged from the tapered section of the crankshaft. 2 Flywheel Puller Kit a Flywheel Puller Plate b Flywheel Puller Plate...
Page 79 Disconnect the pulse coil connector 5 and remove the fuse holder 6, battery cable 7, and ground lead wire 8. Remove the coil bracket assembly 9. Turn the drive pulley 0 in the clockwise direction, and align the “ ” mark d of the drive pulley with the “ ” mark e of the cylinder block.
Page 80 Maintenance Make sure that the “ I” mark f of the driven pulley q and the “ ” mark g of the cylinder head align. Make sure that the “ ” mark d of the drive pulley 0 and the “ ” mark e of the cylinder block align. Install a new timing belt e.
Page 81 Install the coil bracket assembly 9. Install the ground lead wire 8, battery cable 7 as well as fuse holder 6 and connect the pulser coil connector 5. Install the alternator assembly 4 and connect the alternator assembly coupler. Install the key in the crankshaft, then install the flywheel 3, washer, and flywheel bolt.
Page 82: Inspection Of Spark Plugs
Maintenance 13) Inspection of Spark Plugs Remove the plug caps 1, then remove the spark plugs 2. Use a spark plug cleaner or wire brush to clean the spark plug electrodes 3. Replace if necessary. Check the electrode for any corrosion or excessive buildup of carbon, and the washer 4 for any damage.
Page 83: Inspection Of Compression Pressure
14) Inspection of Compression Pressure Start the engine to warm up for 5 minutes, then stop the engine. Shift the gear into the Neutral (N) position. Remove lock plate (stop switch lanyard) from stop switch. CAUTION Remove lock plate (stop switch lanyard) f r o m s t o p s w i t c h b e f o r e m e a s u r i n g compression pressure.
Page 84: Inspection And Adjustment Of Valve Clearance
Maintenance 15) Inspection and Adjustment of Valve Clearance • Perform inspection and adjustment of valve clearances when engine is cold. • Be sure to perform inspection and adjustment of valve clearances while the cylinder head bolt is tightened. • The No.1 cylinder should be at the top dead center of the compression stroke.
Page 85: Adjustment Of Throttle Cable (Basic Tiller Handle Model)
16) Adjustment of Throttle Cable (Basic Tiller Handle Model) Set the throttle grip to its fully closed position. Adjust the throttle cable 3 and tighten the nut 4 so that the stopper a of the throttle drum 1 contacts the stopper b of the throttle cable bracket 2.
Page 86: Adjustment Of Shift • Throttle Cable (Multi-Function Tiller Handle Model)
Maintenance Install the throttle link 7 on the throttle drum. Check that the stopper e of the throttle valve contacts the stopper f of the throttle body 8. If not contacting, check standard length of throttle link. Turn the throttle grip to its fully open and fully closed positions several times to check.
Page 87 Turn the shift arm 4 to the Forward (F), Neutral (N) or Reverse (R) position, then turn it to the Neutral (N) position after confirming the position. Adjust the screw-in amount of the cable joint 3 so that the hole of the cable joint is aligned with the throttle arm and shift arm pin a .
Page 88 Maintenance Set the throttle grip to its fully open position and check that the stopper c of the throttle arm contacts with the projection d on the crankcase. Next, check that the throttle body on the outboard motor side is fully closed when the throttle grip is returned to its original position.
Page 89: Adjustment Of Shift • Throttle Cable (Remote Control Model)
18) Adjustment of Shift • Throttle Cable (Remote Control Model) CAUTION S h i f t o p e r a t i o n s c a n n o t b e c a r r i e d out unless the throttle is fully closed.
Page 90 Maintenance Adjust the screw-in amount of the cable joint so that the hole of the cable joint 3 is aligned with the throttle arm and shift arm 4 pin a . WARNING Screw in a minimum of 10 mm (0.39 in) b of the cable joint.
Page 91 Lower the control lever 2 to the Forward (F) side until the motor shifts in. Lower the lever further and check that the stopper c of the throttle arm contacts with the projection d on the crankcase. Next, check that the throttle valve is fully closed when the control lever is returned to the neutral position (N).
Page 92: Inspection Of Shift Lever Gear Operations
Maintenance 19) Inspection of Shift Lever Gear Operations Shift the gear from neutral (N) to forward (F) or reverse (R) and check that the gear changes smoothly. Adjust the position of the shift arm 1 and the joint position of the shift rod as well as the cam rod if necessary.
Page 93: Inspection Of Pt Unit Operation
Connect the cable joint, attach the washer and R pin 8, and tighten the lock nut 9. (Multi-Function Tiller Handle Control Model, Remote Control Model) Check if the gear shifts smoothly, and repeat Steps 2 to 6 where necessary. 20) Inspection of PT Unit Operation Tilt up and down the outboard motor several times to check that the manual tilt operates smoothly throughout the entire range.
Page 94: Inspection Of Manual Tilt Operations
Maintenance Tilt up the outboard motor adequately and set the lock lever 2 to the locking position to check that the manual holding mechanism of gas shock absorber 3 functions normally. If any problem is found as a result of the inspection, replace the gas shock absorber.
Page 95: Inspection Of Idle Speed
If the PT fluid level is insufficient, replenish the PT fluid to the prescribed level. PT Fluid: ATF DEXRON III PT Fluid Quantity (Reference): 260 mL (8.893 US fl.oz.) Attach the reserve tank cap and tighten it to the specified torque.
Page 96: Inspection Of Anodes
Maintenance 26) Inspection of Anodes Inspection of Conductivity CAUTION If the anode is not getting smaller, there is a possibility Do not coat the anode or trim tab with that conductivity is not being maintained correctly. oil, grease or paint, or their anti-galvanic Follow the procedure below to check the anode.
Page 97: Replacement Of Anodes
27) Replacement of Anodes Anodes protect the outboard motor from galvanic corrosion (corrosion of metal due to very weak electric current). Anodes are used in the gear case, mount rubber (lower), swivel bracket, clamp bracket, PT unit assy, and power unit.
Page 98: Inspection Of Propeller
Maintenance 29) Inspection of Propeller Check the propeller blades and splines for cracks, damage, wear, and corrosion. Replace if necessary. 30) Inspection of Thermostat Remove the thermostat cover 1 and gasket 2 , then remove the thermostat 3 . Hang the thermostat in a vessel containing water. Put thermometer in the water, and warm up water to measure valve opening temperature.
Page 99: Inspection Of Cooling Water Pressure
31) Inspection of Cooling Water Passage Check the water strainer 1 for clogging. Clean if necessary. Place the outboard motor in the water and start the engine. Check that cooling water is discharged from cooling water check port 2. If not, check the water pump and cooling water passage in the engine.
Page 100: Flushing With Water
Maintenance 33) Flushing with Water WARNING Exhaust gas contains carbon monoxide, which may result in gas poisoning. Do not start the engine with the outboard motor placed in an enclosed area such as a boat house etc. CAUTION Touching a rotating propeller may lead to injury.
Page 101: Inspection Of Battery
34) Inspection of Battery Inspect the electrolyte level. If it is lower than the “LOW” mark a, add distilled water until the level is between the “UP” and “LOW” marks. Measure the specific gravity of the electrolyte. Fully charge the battery if the specific gravity is less than the specified value.
Page 102: Grease Points
Maintenance 35) Grease points Apply water proof grease to the parts shown below or pour it via grease nipples. 3-38 4st 25/30 2022...
Page 103 Fuel System (Fuel Injection) 1. Special Tools ……………………………… 4-2 2) Waring Notification, Abnormality and 2. Piping Arrangement Diagram ……… 4-3 Action to be taken ……………………… 4-24 Fuel Hose, Vent Hose, Breather Hose, 5. Ignition System ………………………… 4-25 Cooling Water Hose ………………………… 4-3 (1) Configuration of Ignition System …...
Page 104: Special Tools
Fuel System (Fuel Injection) 1. Special Tools Vacuum/Pressure Gauge Pressure Gauge Assembly Tachometer P/N. 3AC-99020-1 P/N. 3T5-72880-0 P/N. 3AC-99010-0 Measurement of Measurement of engine Inspection of pressure fuel pressure revolution speed 4st 25/30 2022...
Page 105: Piping Arrangement Diagram
2. Piping Arrangement Diagram Fuel Hose, Vent Hose, Breather Hose, Cooling Water Hose Ref. Parts Name 1 Fuel Hose (Fuel Connector Fuel Filter) 2 Fuel Hose (Fuel Filter Fuel Pump) 3 Fuel Hose (Fuel Pump Vapor Separator) 4 Breather Hose (Cylinder Head Intake Silencer) 5 Breather Hose (Cylinder Head Cylinder Block)
Page 106: Parts Layout
Fuel System (Fuel Injection) 3. Parts Layout Intake Manifold 6.0 N·m (4.4 lb·ft) [0.6 kgf·m] 2.5 N·m (2 lb·ft) [0.25 kgf·m] 2.5 N·m (2 lb·ft) [0.25 kgf·m] Fig.5-1 5.5 N·m (4.0 lb·ft) [0.55 kgf·m] Fig.7-23 Fig.7-23 Fig.6-1 Fig.7-23 Fig.3-43 9.0 N·m (6.6 lb·ft) [0.9 kgf·m] Fig.10-16 4st 25/30 2022...
Page 107 Ref. Parts Name Q'ty Remarks Intake Manifold Gasket Do not reuse. Throttle Body Assy Bolt Gasket Do not reuse. Intake Silencer Assy Bolt Fuel Rail O-ring 1.9-9.8 Do not reuse. Valve Assy (Pressure Check) Nipple Holding Plate Bolt Fuel Injector Assy Seal Ring Do not reuse.
Page 108 Fuel System (Fuel Injection) Fuel System Fig.5-31 Fig.5-30 Fig.5-1 Fig.17-6 Fig.10-1 35 36 Fig.17-26 Fig.17-1 4st 25/30 2022...
Page 109 Ref. Parts Name Q'ty Remarks Vapor Separator Assy Cover Seal Screw Drain Screw Gasket Do not reuse. Float Valve Assy Float Arm Pin Float Grommet Filter (Inlet) Holder Fuel Feed Pump O-ring Do not reuse. O-ring Do not reuse. O-ring Do not reuse.
Page 110 Fuel System (Fuel Injection) Fig.5-31 Fig.5-30 Fig.5-1 Fig.17-6 Fig.10-1 35 36 Fig.17-26 Fig.17-1 4st 25/30 2022...
Page 111 Ref. Parts Name Q'ty Remarks 43-1 Fuel Hose W/Protector 43-2 Fuel Hose W/Protector Water Hose Water Hose 46-1 Fuel Hose W/Protector 46-2 Fuel Hose W/Protector Fuel Hose W/Protector Adapter Cord L=200 52-1 Fuel Hose W/Protector 52-2 Fuel Hose W/Protector Fuel Hose Joint Plug Band Do not reuse.
Page 112: Magneto
Fuel System (Fuel Injection) Magneto 70 N·m (52 lb·ft) [7.0 kgf·m] EF/E/ET Fig.9-48 Fig.9-31 Fig.9-48 Fig.9-31 4-10 4st 25/30 2022...
Page 113 Ref. Parts Name Q'ty Remarks Flywheel W/Gear Alternator Assy Alternator Assy Key 13.4-5-4 Bolt Washer 13-26-3.2 Bolt Starter Pulley Bolt Coil Bracket Bolt Pulsar Coil Pulsar Coil Bolt Starter Lock Cable Bracket Bolt Cable Terminal Holder Bolt Fuse Holder Bracket Screw Bracket Bolt...
Page 114: Electrical Parts
Fuel System (Fuel Injection) Electrical Parts Fig.1-31 8 N·m (6 lb·ft) [0.8 kgf·m] Fig.8-34 43 42 4-12 4st 25/30 2022...
Page 115 Ref. Parts Name Q'ty Remarks Oil Pressure Switch Rectifier Complete Cover Bolt Starter Motor Assy Pinion Assy Washer Brush Holder Assy Screw Bushing 2 O-ring Do not reuse. Bushing 1 Washer Spring Washer Bolt Spring Washer Washer Bolt Starter Motor Band Damper Bolt Battery Cable L=2500...
Page 116 Fuel System (Fuel Injection) Fig.1-31 8 N·m (6 lb·ft) [0.8 kgf·m] Fig.8-34 43 42 4-14 4st 25/30 2022...
Page 117 Ref. Parts Name Q'ty Remarks Bolt Washer 6-16-1.5 Rubber Mount Collar Plate Bolt Plate Band Engine Temp Sensor 51-1 ECU Assy (25DO) 51-2 ECU Assy (30DO) 51-3 ECU Assy (25) 51-4 ECU Assy (30) Bolt Washer 6-16-1.5 Spacer 6.2-9-27 Bolt Band Do not reuse.
Page 118: Fuel Tank
Fuel System (Fuel Injection) Fuel Tank 4-16 4st 25/30 2022...
Page 119 Ref. Parts Name Q'ty Remarks Primer Bulb Assy Joint Assy (Inlet) Joint Assy (Outlet) Primer Bulb Clamp Hose Hose Fuel Connector Fuel Connector Clamp Primer Bulb Assy W/Band Band Do not reuse. Fuel Tank Assy 25L Tank Filler Cap Gasket Do not reuse.
Page 120: Ecu System
Fuel System (Fuel Injection) 4. ECU System (1) Configuration of ECU System The ECU uses various sensors to precisely control the injected fuel amount and ignition timing. 1 Fuel Tank 2 Fuel Regulator 3 Vapor Separator 4 Fuel Feed Pump (FFP) 5 ECU 6 Ignition Coil...
Page 121: Sensors
1) Sensors Individual sensors detect the engine operating conditions and sends signals regarding the information to the ECU. Pulser Coil [Crank Position Sensor] Pulser coils function as crank position sensors. As the crank position in 120° and sends a crank position signal to the ECU.
Page 122: Actuators
Fuel System (Fuel Injection) Oil Pressure Switch The oil pressure switch is located on the port side of the engine block, protruding into the oil passage. The oil pressure switch sends an oil pressure low signal to the ECU. The ECU activates the low speed ESG and warning lamp based on this information.
Page 123: Control System (Ecu)
4. Controls the engine low speed ESG function. 5. Controls the engine high speed ESG function. 6. Memorizes engine operation information. Monitoring and failure diagnosis can be carried out using a PC on which TOHATSU DIAGNOSTICS (software) is installed and diagnostics harness. (2) Control System The ECU (Electronic Control Unit) is installed in the cylinder block via a bracket.
Page 124: Fuel Injection Control
Fuel System (Fuel Injection) (3) Fuel Injection Control The ECU calculates the intake air quantity based on the engine revolution speed and intake manifold pressure (intake vacuum pressure) to determine the fuel injection amount. During engine startup, warm-up, acceleration/deceleration, and idling, the ECU performs correction control based on information from the sensors.
Page 125: Start Up Fuel Mapping
2) Start Up Fuel Mapping When the engine is started (cranked), the amount of fuel injected by each cylinder is increased from the normal quantity to improve the starting performance. In addition, the block temperature and other information is obtained from the various sensors and corrected to the optimum condition.
Page 126: Warning Buzzer And Lamp (Led), And Control Of Engine Revolution Speed
Fuel System (Fuel Injection) (6) Warning Buzzer and Lamp (LED), and Control of Engine Revolution Speed Warning System When an abnormality occurs on the engine, warning buzzer sounds and warning lamp (LED) is lit or blinks. In such case, engine speed is controlled but engine is not stopped. 1) Location of Warning Buzzer and Lamp (LED) •...
Page 127: Ignition System
5. Ignition System For ignition system, CD ignition system is adopted, and ECU's electronic ignition timing control system controls the timing to the most suitable state according to current operating conditions. As engine is started, electric current is generated in the exciter coil of alternator. Which is input to ECU's regulator to feed power needed for operations of ignition coil, fuel injector and fuel feed pump (FFP).
Page 128: Ignition Control
Fuel System (Fuel Injection) (2) Ignition Control The ECU's microcomputer is pre-programmed with optimal ignition timings according to the condition of the engine. The ECU obtains information about the engine operating status such as the revolution speed, throttle opening, manifold pressure (air intake vacuum pressure), cooling water temperature etc. based on the signals from the above- mentioned sensors to ignite the fuel at the optimal ignition timing.
Page 129: Fuel Feed System
(3) Fuel Feed System Fuel pump 4 (low pressure mechanical type) draws fuel from fuel tank, and feeds it to fuel feed pump 6 (FFP) located in the vapor separator 5 through fuel connector 2 and fuel filter 3. Highly pressurized fuel, fed into fuel rail 8 and fuel injector, and then, injected into intake manifold. Excessive fuel that is not used by fuel injector passes through fuel regulator 7, and circulated in the vapor separator 5 to keep fuel pressure constant.
Page 130: Components Of Fuel Feed System
Fuel System (Fuel Injection) 6. Components of Fuel Feed System 1) Fuel Pump [Low Pressure Mechanical Pump] The fuel pump is a diaphragm pump that is operated mechanically by the camshaft. a IN: Fuel from Filter/Tank b OUT: Fuel Outlet to Vapor Separator 2) Vapor Separator Vapor separator feeds only liquid fuel for internal fuel feed pump (FFP) 1 (electrical high pressure pump).
Page 131: Fuel Regulator
3) Fuel Regulator The fuel regulator located inside the vapor separator serves to keep the fuel pressure constant. The fuel regulator consists of a check valve to actuate the valve/seat, returning the excess fuel b (pressurized) to the vapor separator when the pressure exceeds a certain value. Excess fuel is returned to the vapor separator through an internal pipe below the fuel level to prevent it from bubbling.
Page 132: Outline Of Fuel Injection System
Fuel System (Fuel Injection) 7. Outline of Fuel Injection System 1) Air Intake System The air intake system consists of components including the intake manifold 1 (air intake passage to cylinders that are linked to a common air chamber), throttle position sensor 2, throttle body/shutter 3, ISC (idle speed control) valve 4, and T-MAP (manifold pressure and temperature) sensor 5.
Page 133: Inspection Items
8. Inspection Items 1) Inspection of Fuel Supply System Check the fuel system piping for fuel leak, dirt, deterioration and damage, and replace or repair parts if necessary. 2) Inspection of Filter Check if there is any dirt in fuel filter 1, or if there is any fuel varnish, debris, deposits and contamination by foreign matter or water in the fuel filter cup 2, or if there are any cracks.
Page 134 Fuel System (Fuel Injection) Cleaning Fuel Feed Pump (FFP) Filter Remove the fuel filter (suction side) 7 from the fuel feed pump (FFP) in the vapor separator and clean it. 4-32 4st 25/30 2022...
Page 135: Inspection Of Fuel Pump
3) Inspection of Fuel Pump Remove the fuel hoses (2 pcs.) from the fuel pump. Connect the vacuum/pressure gauge to the inlet of the fuel pump. Close the fuel pump outlet with your finger and apply the specified pressure. Make sure there are no air leaks. Vacuum/Pressure Gauge: P/N.
Page 136: Measurement Of Fuel Pressure
Fuel System (Fuel Injection) 5) Measurement of Fuel Pressure Remove the cap 1. Connect the pressure gauge 2 as shown in the figure. WARNING • Before measurement, check that the pressure relief valve is fully closed. • Before connecting the pressure gauge, c o v e r t h e c o n n e c t i o n b e t w e e n t h e pressure gauge and valve with a clean and dry cloth to prevent fuel from leaking.
Page 137: Draining Fuel
6) Draining Fuel Remove the cap 1. Connect the pressure gauge assembly 2 as shown in the figure, place a vessel below the pressure relief hose, and open the pressure relief valve 3 to release the fuel pressure. WARNING Be sure to reduce the fuel pressure in the high pressure fuel passage before servicing the fuel passage and/or vapor separator.
Page 138: Disassembly Of Vapor Separator
Fuel System (Fuel Injection) 7) Disassembly of Vapor Separator WARNING Be sure to reduce the fuel pressure in the high pressure fuel passage before servicing the fuel passage and/or vapor separator. Performing the service without releasing the pressure causes compressed fuel to be injected, possibly causing a hazard.
Page 139: Inspection Of Vapor Separator
8) Inspection of Vapor Separator Check the needle valve for bend and wear. Replace if necessary. Check the float for deformation. Replace if necessary. Check the filter for dirt and clogging. Clean if necessary. Reinstall the needle valve, float and float pin, and check that the parts moves smoothly.
Page 140: Inspection Of Isc (Idle Speed Control)
Fuel System (Fuel Injection) 10) Inspection of ISC (Idle Speed Control) Use the diagnosis system to check operation of the ISC (Idle Speed Control) valve. The value may be significantly higher than the reference value when there is abnormality in the engine. ISC Duty Ratio: 10-30% (after warming-up, idle speed 850 min (rpm))
Page 141 Power Unit 1. Special Tools ……………………………… 5-2 23) Inspection of Cylinder Head …………… 5-58 2. Parts Layout ……………………………… 5-3 24) Inspection of Oil Pump ………………… 5-59 Engine ………………………………………… 5-3 25) Installation of Valve ……………………… 5-60 Magneto ……………………………………… 5-4 26) Installation of Camshaft ………………… 5-61 Intake Manifold ………………………………...
Page 142 Power Unit 1. Special Tools Compression Gauge Torque Wrench Valve Clearance Driver Crank Shaft Holder P/N. 3AC-99030-0 P/N. 3AC-99070-0 P/N. 3AC-99071-0 P/N. 3BJ-72815-0 Measuring compression Adjusting valve clearance Adjusting valve clearance Holding crankshaft pressure ø34.5 x ø17.5 Flywheel Puller Kit Oil Seal Attachment Oil Filter Wrench P/N.
Page 143 2. Parts Layout Engine 1 15 N·m (11 lb·ft) [1.5 kgf·m] 2 30 N·m (22 lb·ft) [3.0 kgf·m] Ref. Ref. Part Name Remarks Part Name Remarks Q'ty Q'ty 1 Recoil Starter 10 Cable Clip 2 Belt Cover 11 Grommet (Lower) 3 Starter Pulley 12 Shift Rod 4 Power Unit...
Page 144 Power Unit Magneto 70 N·m (52 lb·ft) [7.0 kgf·m] EF/E/ET Fig.9-48 Fig.9-31 Fig.9-48 Fig.9-31 4st 25/30 2022...
Page 145 Ref. Parts Name Q'ty Remarks Flywheel W/Gear Alternator Assy Alternator Assy Key 13.4-5-4 Bolt Washer 13-26-3.2 Bolt Starter Pulley Bolt Coil Bracket Bolt Pulsar Coil Pulsar Coil Bolt Starter Lock Cable Bracket Bolt Cable Terminal Holder Bolt Fuse Holder Bracket Screw Bracket Bolt...
Page 146 Power Unit Intake Manifold 6.0 N·m (4.4 lb·ft) [0.6 kgf·m] 2.5 N·m (2 lb·ft) [0.25 kgf·m] 2.5 N·m (2 lb·ft) [0.25 kgf·m] 24 25 Fig.5-1 5.5 N·m (4.0 lb·ft) [0.55 kgf·m] Fig.7-23 Fig.7-23 Fig.6-1 Fig.7-23 Fig.3-43 9.0 N·m (6.6 lb·ft) [0.9 kgf·m] Fig.10-16 4st 25/30 2022...
Page 147 Ref. Parts Name Q'ty Remarks Intake Manifold Gasket Do not reuse. Throttle Body Assy Bolt Gasket Do not reuse. Intake Silencer Assy Bolt Fuel Rail O-ring 1.9-9.8 Do not reuse. Valve Assy (Pressure Check) Nipple Holding Plate Bolt Fuel Injector Assy Seal Ring Do not reuse.
Page 148 Power Unit Fuel System Fig.5-31 Fig.5-30 Fig.5-1 Fig.17-6 Fig.10-1 35 36 Fig.17-26 Fig.17-1 4st 25/30 2022...
Page 149 Ref. Parts Name Q'ty Remarks Vapor Separator Assy Cover Seal Screw Drain Screw Gasket Do not reuse. Float Valve Assy Float Arm Pin Float Grommet Filter (Inlet) Holder Fuel Feed Pump O-ring Do not reuse. O-ring Do not reuse. O-ring Do not reuse.
Page 150 Power Unit Fig.5-31 Fig.5-30 Fig.5-1 Fig.17-6 Fig.10-1 35 36 Fig.17-26 Fig.17-1 5-10 4st 25/30 2022...
Page 151 Ref. Parts Name Q'ty Remarks 43-1 Fuel Hose W/Protector 43-2 Fuel Hose W/Protector Water Hose Water Hose 46-1 Fuel Hose W/Protector 46-2 Fuel Hose W/Protector Fuel Hose W/Protector Adapter Cord L=200 52-1 Fuel Hose W/Protector 52-2 Fuel Hose W/Protector Fuel Hose Joint Plug Band Do not reuse.
Page 152 Power Unit Electrical Parts Fig.1-31 8 N·m (6 lb·ft) [0.8 kgf·m] Fig.8-34 43 42 5-12 4st 25/30 2022...
Page 153 Ref. Parts Name Q'ty Remarks Oil Pressure Switch Rectifier Complete Cover Bolt Bolt Starter Motor Assy Pinion Assy Washer Brush Holder Assy Screw Bushing 2 O-ring Do not reuse. Bushing 1 Washer Spring Washer Bolt Spring Washer Washer Bolt Starter Motor Band Damper Bolt Battery Cable L=2500...
Page 154 Power Unit Fig.1-31 8 N·m (6 lb·ft) [0.8 kgf·m] Fig.8-34 43 42 5-14 4st 25/30 2022...
Page 155 Ref. Parts Name Q'ty Remarks Bolt Washer 6-16-1.5 Rubber Mount Collar Plate Bolt Plate Band Engine Temp Sensor 51-1 ECU Assy (25DO) 51-2 ECU Assy (30DO) 51-3 ECU Assy (25) 51-4 ECU Assy (30) Bolt Washer 6-16-1.5 Spacer 6.2-9-27 Bolt Band Do not reuse.
Page 156 Power Unit Pulley & Timing Belt 11 N·m (8 lb·ft) [1.1 kgf·m] 64 N·m (47 lb·ft) [6.4 kgf·m] 5-16 4st 25/30 2022...
Page 157 Ref. Part Name Q'ty Remarks Drive Pulley Key 10-3.7-3 Belt Guide Driven Pulley Key 10-3.7-3 Washer 6.5-19-3.2 Pre-Coated Bolt 6-20 Timing Belt 5-17 4st 25/30 2022...
Page 158 Power Unit Cylinder Head & Oil Pump 1 10 N·m (7 lb·ft) [1.0 kgf·m] 2 30 N·m (22 lb·ft) [3.0 kgf·m] 1 6 N·m (4 lb·ft) [0.6 kgf·m] 2 10 N·m (7 lb·ft) [1.0 kgf·m] 7 N·m (5 lb·ft) [0.7 kgf·m] Fig.5-6 Fig.1-1 18 N·m (13 lb·ft) [1.8 kgf·m]...
Page 159 Ref. Part Name Q'ty Remarks Cylinder Head Complete Cylinder Head Assy Camshaft Assy Oil Seal 18-35-8 Do not reuse. Rocker Arm Adjusting Screw Adjusting Nut Rocker Arm Shaft Rocker Shaft Spring Washer 13.2-21.8-2 Collar Valve Spring Valve Spring Seat Intake Valve Stem Seal Gray Do not reuse.
Page 160 Power Unit 1 10 N·m (7 lb·ft) [1.0 kgf·m] 2 30 N·m (22 lb·ft) [3.0 kgf·m] 1 6 N·m (4 lb·ft) [0.6 kgf·m] 2 10 N·m (7 lb·ft) [1.0 kgf·m] 7 N·m (5 lb·ft) [0.7 kgf·m] Fig.5-6 Fig.1-1 18 N·m (13 lb·ft) [1.8 kgf·m] 18 N·m (13 lb·ft) [1.8 kgf·m] 1.5 N·m (1.1 lb·ft) [0.15 kgf·m] 2.5 N·m (1.8 lb·ft) [0.25 kgf·m]...
Page 161 Ref. Part Name Q'ty Remarks Spark Plug (DCPR6E) Breather Hose Breather Hose W/Protector Cylinder Head Gasket Do not reuse. Washer Intake Valve Kit Intake Valve Retainer Cotter Exhaust Valve Kit Exhaust Valve Retainer Cotter 5-21 4st 25/30 2022...
Page 162 Power Unit Cylinder & Crankcase 9.0 N·m (6.6 lb·ft) [0.9 kgf·m] 30 N·m (22 lb·ft) [3.0 kgf·m] Fig.9-4 Fig.9-3 1 Rotate 3/4 (270°) with your finger. 2 18 N·m (13 lb·ft) [1.8 kgf·m] 1 6 N·m (4 lb·ft) [0.6 kgf·m] 2 11.5 N·m (8.5 lb·ft) [1.2 kgf·m] 1 10 N·m (7 lb·ft) [1.0 kgf·m] 2 23.5 N·m (18 lb·ft) [2.4 kgf·m]...
Page 163 Ref. Part Name Q'ty Remarks Cyl Block & Crankcase Assy Dowel Pin 6-12 Oil Filter Bolt Bolt M8-70-P1.25 Bolt Washer Oil Drip Tray Plug Collar Bolt Washer Thermostat Thermostat Cap Thermostat Cap Gasket Do not reuse. Bolt L=35mm Exhaust Cover (Outer) Exhaust Cover Gasket Do not reuse.
Page 164 Power Unit Piston & Crankshaft 1 6 N·m (4 lb·ft) [0.6 kgf·m] 2 10 N·m (7 lb·ft) [1.0 kgf·m] 5-24 4st 25/30 2022...
Page 165 Ref. Part Name Q'ty Remarks Crankshaft Assy Plain Shaft Bearing 34-37-15 Plain Shaft Bearing 34-37-15 Oil Seal 36-50-7 Do not reuse. Oil Seal 32-44-9 Do not reuse. Connecting Rod Assy Connecting Rod Bolt Piston Repair Kit Piston Piston Pin Piston Pin Clip Do not reuse.
Page 166 Power Unit Top Cowl 5-26 4st 25/30 2022...
Page 167 Ref. Part Name Q'ty Remarks Top Cowl Assy Top Cowl Sub-Assy Top Cowl Seal Side Decal Logo Decal Rear Decal (25) Rear Decal (30) Simpliq Decal Caution Decal (A) Caution Decal 5-27 4st 25/30 2022...
Page 168 Power Unit Recoil Starter Fig.3-34 6 N·m (4 lb·ft) [0.6 kgf·m] 5-28 4st 25/30 2022...
Page 169 Ref. Part Name Q'ty Remarks Recoil Starter Assy Bushing Starter Spring Reel Ratchet E-Ring d=10 Do not reuse. Return Spring Return Spring Friction Plate Tapping Screw Starter Handle Rope Anchor Starter Lock Starter Lock Spring Friction Spring Starter Lock Cam Spring Seal Starter Lock Wire Starter Seal...
Page 170 Power Unit 3. Inspection Items 1) Inspection of Compression Pressure Refer to “Inspection of Compression Pressure” in Chapter 3. Compression Pressure (reference value): At 500 min (rpm) With decompressor: 0.50 MPa (73 psi) [5.1 kgf/cm ² Without decompressor: 1.40 MPa (203 psi ) [14.3 kgf/cm ²...
Page 171 3) Inspection of Valve Clearance Refer to "Inspection and Adjustment of Valve Clearance" in Chapter 3. Valve Clearance (when engine is cold): Intake Side: 0.10–0.15 mm (0.0040–0.0060 in) Exhaust Side: 0.20–0.24 mm (0.0080–0.0095 in) 4) Removal of Power Unit Remove the oil level gauge 1 . Remove the apron 2 .
Page 172 Power Unit Remove the battery cable 6 . (Electric Starter Model) Disconnect the indicator lamp connector 7 . Disconnect the PT switch coupler 8 and PT motor coupler 9. (Power Tilt Model) Disconnect the fuel hose 0 . Remove the cooling water hose (vapor separator - cooling water check port) q .
Page 173 Disconnect the vent hose w , cooling water hose (drive shaft housing - vapor separator) e , and vapor separator drain hose r . Remove the power unit installation bolts. Loosen the power unit installation bolts in the order shown in the diagram. A Starboard B Port Remove the starter lock cable t, and remove the recoil...
Page 174 Power Unit Remove the starter pulley o. Hoist and remove the power unit. • Install the eye bolt p in the screw hole for installing the starter pulley. • When hoisting the power unit, do so carefully while checking if the wires and hoses are caught by other parts.
Page 175 7) Removal of Flywheel Use the flywheel puller kit 1 to loosen the flywheel bolt and remove the flywheel bolt. Flywheel Puller Kit 1: P/N. 3T1-72211-4 Use the flywheel puller kit to remove the flywheel 2 and key. Screw the puller onto the crankshaft end until the flywheel is disengaged from the tapered portion of the crankshaft.
Page 176 Power Unit CAUTION To prevent damage to the engine and special tools, tighten the flywheel puller set bolts evenly and keep the flywheel puller plate parallel to the flywheel while working. Disconnect the alternator assy couplers, and remove the alternator assy 3. Disconnect the pulser coil connectors 4, and remove the fuse holder 5, battery cable 6, and ground lead wires 7.
Page 177 8) Installation of Flywheel Install the coil bracket assy 1. Install the ground lead wires 2, battery cable 3, and fuse holder 4, and connect the pulser coil connectors 5. Install the alternator assy 6, and connect the alternator assy coupler. Install the key in the crankshaft, and then install the flywheel 7, washer and flywheel bolt.
Page 178 Power Unit Install the starter pulley 9. Install the belt cover 0, and connect the vent hoses q. Install the recoil starter w, and install the starter lock cable 5-38 4st 25/30 2022...
Page 179 9) Removal of Timing Belt and Pulley Turn the drive pulley 1 in the clockwise direction, and align the “ ” mark a of the drive pulley with the “ ” mark b of the cylinder block. Check that the “ c of the driven pulley 2 and the “...
Page 180 Power Unit Remove the timing belt 7. Remove the timing belt from the driven pulley 2 side. Remove the driven pulley 2. Remove the nut 5 of the drive pulley, the belt guide 8, the drive pulley 9, and the key 0. 10) Inspection of Timing Belt Check the timing belt for cracks, damage, and wear on both faces.
Page 181 11) Installation of Pulley and Timing Belt CAUTION Do not turn the drive pulley or the driven pulley with the timing belt removed. Doing so can make pistons and valves interfere with each other, possibly resulting in damages to these parts. Install the key 1, the drive pulley 2, the belt guide 3, and the nut 4 of the drive pulley.
Page 182 Power Unit Install the timing belt 6. CAUTION • Be careful not to damage the timing belt during installation. • Do not twist, turn inside out, or sharply bend the timing belt. Doing so may cause damage. • Be careful not to allow oil or grease to adhere to the timing belt.
Page 183 Turn the crankshaft two full rotations in the clockwise direction, and check that the alignment marks of the pulleys are aligned. • Check that the crankshaft turns smoothly. • Make sure the “ ” mark a of the drive pulley is aligned with the “...
Page 184 Power Unit Disconnect vent hose 6. Disconnect the injector couplers 7. Disconnect the fuel feed pump coupler 8 of the vapor separator. Disconnect the ISC coupler 9, the T-MAP sensor coupler 0, and the throttle position sensor coupler q. 5-44 4st 25/30 2022...
Page 185 Remove the throttle link w (throttle valve side). A Basic Tiller Handle Model B Multi-Function Tiller Handle Model, Remote Control Model Remove the fuel filter e from the plate. Remove the fuel pump r from the head cover. Remove the intake manifold assy t. 5-45 4st 25/30 2022...
Page 186 Power Unit 13) Removal of Electrical System Parts Remove the air intake system parts and fuel system parts. Refer to the section on removing the air intake system & fuel system (5-43) Remove the flywheel, alternator assy, and coil bracket assy.
Page 187 Remove the ground lead wire 9 and the PT relay plate 0. (Power Tilt Model) Disconnect the rectifier coupler q. (Electric Starter Model) Remove the ground lead wire w. Remove the ground lead wire e (Power Tilt Model) and oil pressure switch lead wire r.
Page 188 Power Unit Remove the rectifier i. (Electric Starter Model) Remove the neutral switch o. (Electric Starter Model) Remove the starter motor p. (Electric Starter Model) 5-48 4st 25/30 2022...
Page 189 14) Removal of Cylinder Head Assy Remove the flywheel. (Refer to the section on removing the flywheel. 5-35) Remove the timing belt and the driven pulley. (Refer to the section on removing the timing belt and pulley. 5-39) Remove the air intake system parts and fuel system parts. (Refer to the section on removing the air intake system &...
Page 190 Power Unit Remove the cylinder head cover 5. Remove the cylinder head bolts in the order shown in the diagram, and remove the cylinder head assy. CAUTION Do not scratch or damage the mating surfaces of the cylinder head and cylinder block.
Page 191 Remove the camshaft 8. CAUTION Pull out slowly so as not to hit the journals. Remove the oil seal 9. Compress the valve spring 0 by using the compressor q, remove the cotter w, and then remove the valve spring and valve e.
Page 192 Power Unit 17) Inspection of Valve Check the valve for dents and wear on the face. Replace if necessary. Measure the valve stem outer diameter a. Replace if less than the specified value. Valve Stem Outer Diameter a: Standard Value Intake Side: 5.48 mm (0.2157 in) Exhaust Side: 5.46 mm (0.2150 in) Functional Limit:...
Page 193 19) Inspection of Valve Seat Remove the carbon built up on the valve. Evenly apply a thin coat of red lead to the valve seat. Use a valve lapper (commercially available) to push the valve onto the valve seat lightly as shown in the diagram. Measure the valve seat contact width a of the valve face stained with red lead.
Page 194 Power Unit 20) Correction of Valve Seat Use a valve seat cutter (commercially available) to correct the valve seat. 30˚ 45˚ 60˚ becomes smooth while rotating the cutter in the clockwise direction. Be careful not to over-grind the valve seat. Rotate the valve seat cutter while pressing it down evenly.
Page 195 c of the valve seat to the specified value. 45˚ b Width before correction c Specified width If the valve seat contact area is located in the center and the area is too wide, adjust the contact width to the specified value by cutting the upper and lower ends using 30˚...
Page 196 Power Unit Apply a thin coat of an abrasive compound to the entire valve seat contact area, and rub and polish the valve seat while knocking and turning the valve with a valve lapper (commercially available). CAUTION Perform the work by taking care not to allow the abrasive compound to adhere to the valve stem and valve guide.
Page 197 22) Inspection of Camshaft Measure the cam height. Replace if less than the specified value. Cam Height a: Standard Value Intake Side: 23.63 mm (0.9303 in) Exhaust Side: 23.80 mm (0.9370 in) Functional Limit: Cam Height a Intake Side: 23.5 mm (0.9252 in) Exhaust Side: 23.5 mm (0.9252 in) Measure the camshaft runout.
Page 198 Power Unit 23) Inspection of Cylinder Head Remove the carbon build-up of the combustion chamber, and check for deterioration, corrosion of mating surfaces, etc. Use a straight edge 1 and thickness gauge 2 to check the distortion of the cylinder head in the directions shown in the diagram.
Page 199 24) Inspection of Oil Pump Use a micrometer, cylinder gauge, depth gauge, and thickness gauge to measure the dimensions shown below. Replace the oil pump if other than the specified value. Functional Limit Clearance between outer rotor and body a: 0.21 mm (0.0083 in) Clearance between outer and inner rotors b: 0.16 mm (0.0063 in)
Page 200 Power Unit 25) Installation of Valve Install the valve spring seat 1 and new valve stem seal 2 onto the valve guide. • Apply 4-stroke engine oil to the valve spring seat and valve stem seal. • Install the gray valve stem seal on the air intake side and the green valve stem seal on the exhaust side.
Page 201 26) Installation of Camshaft Apply 4-stroke engine oil onto the outer circumference of the new oil seal 1 and install the camshaft with the oil attachment 2. Oil Seal Attachment 2: P/N. 3AC-99820-0 Apply cold-resistant grease to the lip of the oil seal before installing the camshaft.
Page 202 Power Unit Install the rocker arms 2, collars 3, springs 4, washers 5, lifter 6, and collars 7 while inserting the rocker arm shaft 1 into the cylinder head. • Install the lifter in the direction shown in the diagram. •...
Page 203 29) Installation of Cylinder Head Assy The No.1 cylinder should be at the top dead center of the compression stroke. After temporarily assembling the driven pulley, align the a of the pulley 1 to the " " mark b of the "...
Page 204 Power Unit Install the cylinder head cover gasket and cylinder head cover. Apply 4-stroke engine oil to the cylinder head cover gasket. Install the PT relay plate 3. (Power Tilt Model) Install the spark plugs. Spark Plug: 18 N · m (13 lb · ft) [1.8 kgf · m] Install the ground lead wire 4.
Page 205 30) Disassembly of Cylinder Block Loosen the bolts in the order shown in the diagram, and remove the thermostat cover 1, the exhaust cover 2, and the bolts. Remove the oil filter 3 and the oil filter drip tray 4. Wipe off spilled oil completely.
Page 206 Power Unit Remove the connecting rod bolts 6 and connecting rod cap 7, and then remove the crankshaft 8 and oil seals. Remove the metal bearings from the cylinder block and crankcase. Remove the connecting rods and piston assemblies from the cylinder block.
Page 207 32) Inspection of Piston Outer Diameter Measure the piston outer diameter between the specified points. Replace if less than the specified value. Piston Outer Diameter a: Standard Value 60.960 mm (2.4000 in) Measurement Point b: 10 mm (0.3937 in) above piston skirt bottom Functional Limit: 60.90 mm (2.3976 in) 33) Inspection of Cylinder Inner Diameter...
Page 208 Power Unit 34) Inspection of Piston Clearance If the piston clearance is greater than the specified limit, replace the cylinder block, or replace the piston and piston rings as a set, or replace all of them. Piston Clearance (Cylinder inner diameter – Piston outer diameter): 0.020 to 0.055 mm (0.00079 to 0.00217 in) Functional Limit:...
Page 209 37) Inspection of Piston Pins Measure the piston pin outer diameter. Replace the piston pin if less than the specified value. Piston Pin Outer Diameter: Standard Value 16.00 mm (0.62992 in) Functional Limit: 15.97 mm (0.62874 in) Measure the piston pin hole inner diameter a. Replace the piston if greater than the specified value.
Page 210 Power Unit 40) Inspection of Crankshaft Measure the crankshaft journal outer diameters a and crank pin outer diameters b. Replace the crankshaft if less than the specified limit. Crankshaft Journal Outer Diameter a: Standard Value 33.988 to 33.996 mm (1.3381 to 1.3384 in) Crank Pin Outer Diameter b: Standard Value 28.972 to 28.985 mm (1.1406 to 1.1411 in)
Page 211 41) Inspection of Crank Pin Oil Clearance Clean the connecting rod and metal bearings. Re-install the metal bearings. Install the piston 1 to the connecting rod 2 . • Install the piston so that the piston “O” mark a and connecting rod “UP” mark b are located at the positions shown in the diagram.
Page 212 Power Unit Remove the connecting rod cap 6 and measure the width of the crushed Plastigauge 4 on each crank pin 5. Replace the connecting rod 2 or crankshaft if greater than the specified value. Crank Pin Oil Clearance: 0.015 – 0.041 mm (0.0006 – 0.0016 in) Functional Limit: 0.060 mm (0.00236 in) 42) Inspection of Crankshaft Main...
Page 213 Loosen the bolts in the reverse order in several steps. Remove the crankcase and measure the width of the crushed Plastigauge on each main journal. Replace the bearings if greater than the specified limit. Crankshaft Main Journal Oil Clearance: 0.012 to 0.044 mm (0.00047 to 0.00173 in) Functional Limit: 0.060 mm (0.00236 in) If the clearance is less than the specified value,...
Page 214 Power Unit 45) Installation of Piston and Connecting Rod Install the connecting rod 2, piston pin 3 and piston pin clips 4 in the piston 1. • Align the connecting rod “UP” mark a and piston “O” mark b to the positions shown in the diagram.
Page 215 Set the piston into the piston slider 6 with the piston "O" mark on the flywheel side e, and install it in the cylinder. • Before installing, apply molybdenum grease and then 4-stroke engine oil to the piston outer surface, and then apply engine oil to the piston ring and the piston slider.
Page 216 Power Unit Install the connecting rod cap w on the connecting rod, and tighten the connecting rod bolts e to the specified torque in two steps. Connecting Rod Bolts e: First Tightening Torque: 6 N·m (4 lb·ft) [0.6 kgf·m] Second Tightening Torque: 10 N·m (7 lb·ft) [1.0 kgf·m] •...
Page 217 Install the crankcase in the cylinder block. Tighten the crankcase bolts, first the M8 bolts and then the M6 bolts, to about half of the specified torque in the order shown. Then tighten to the specified torque in the order of M8 bolts and M6 bolts.
Page 218 Power Unit Install the shift lever shaft 8. • Apply cold-resistant lithium grease to the shift lever shaft and shift lever shaft installation area. • Apply a screw locking agent (ThreeBond 1342) to the bolts. Install the cylinder head. For the installation procedure, refer to "Installation of Cylinder Head."...
Page 219 3. Install the rectifier 3. (Electric Starter Model) Apply water-resistant grease to the rectifier gasket. Install the oil pressure switch 4 and tighten to the specified torque. Apply a screw locking agent (ThreeBond 1327) to the threaded area of the oil pressure switch. Oil Pressure Switch: 8 N ·...
Page 220 Power Unit Install the PT relay plate q and the ground lead wire w. (Power Tilt Model) Connect the engine temperature sensor coupler e. Install the ground lead wire r. Install the ignition coil bracket assy t. Tighten the ignition coil ground lead wires together with the bolt y.
Page 221 Secure the wire harness with a band a. Install the coil bracket assy, alternator assy, and flywheel. Refer to the section on installing the flywheel (5-37) Install the parts of the air intake system and fuel system. Refer to the section on installing the air intake system &...
Page 222 Power Unit Install the fuel filter 3. The fuel filter should be level with the engine when installed. Install the throttle link 4. Apply cold-resistant lithium grease to the throttle link installation area of the throttle valve. A Basic Tiller Handle Model B Multi-Function Tiller Handle Model, Remote Control Model Connect the throttle position sensor coupler 5, T-MAP...
Page 223 Connect the injector couplers 9. Install the belt cover, and connect the vent hoses 0. Connect the breather hose q and the breather hose w. Secure the wire harness with a band e, and secure the wire harness and pulser coil connector with a band r. Secure the fuel hose with the clamp t.
Page 224 Power Unit 49) Installation of Oil Strainer Install the oil strainer 1 to the hose, and install the hose to the nipple. 50) Installing the Power Unit Clean the mating surface of the power unit, and install a new gasket 1 and nipple 2. Install the dowel pin 3.
Page 225 Install the power unit installation bolts and tighten them to the specified torque in two steps in the order shown in the diagram. Apply water-resistant grease to the power unit installation bolts. Power Unit Installation Bolt: First Tightening Torque: 15 N·m (11 lb·ft) [1.5 kgf·m] Second Tightening Torque: 30 N·m (22 lb·ft) [3.0 kgf·m] Connect the vapor separator drain hose 4, cooling water...
Page 226 Power Unit Connect the PT motor couplers 9 and PT switch coupler 0. (Power Tilt Model) Connect the indicator lamp connectors q. Install the battery cable w. (Electric Starter Model) Install the shift rod e and shift lever rod r (Basic Tiller Model).
Page 227 Install the apron y. Install the apron with the front side extended. Install the starter lock cable u, and install the recoil starter i (three bolts). Install the oil level gauge o. Fill with the specified amount of engine oil. Recommended Engine Oil: 4-Stroke Engine Oil API: SH, SJ, SL...
Page 228 Power Unit 51) Removal of Recoil Starter Adjustment of Starter Lock Cable Shift the gear into neutral (N). Check that the maximum diameter of the slide 1 aligns with the neutral start mark 2. 1 Slide 2 Neutral start mark If not, adjust the lower side of the cable.
Page 229 Remove the starter shaft screw 2 and then the friction plate 3 and spring 4. Take out the reel carefully. Remove the E-ring 5, and remove the ratchet 7, ratchet guide 8, and return spring 9. 5 E-ring 8 Ratchet Guide 6 Reel 9 Return Spring 7 Ratchet...
Page 230 Power Unit 54) Installation of Recoil Starter Assembly is performed in the reverse order of disassembly, but the following points should be noted. face the starter spring outer edge hook to the right and set it into the peripheral cut of the starter case. protrusion of the reel in the inner hook of the starter spring.
Page 231 Lower Unit 1. Special Tools ……………………………… 6-2 18) Assembly of Propeller Shaft Assy ……… 6-23 2. Parts Layout ……………………………… 6-4 19) Removal of Bevel Gear Assy A ………… 6-24 Gear Case (Drive Shaft) …………………… 6-4 20) Disassembly of Bevel Gear Assy A …… 6-24 Gear Case (Propeller Shaft) …………………...
Page 232 Lower Unit 1. Special Tools Spring Pin Tool A Spring Pin Tool B Bevel Gear B Nut Wrench Bevel Gear B Nut Socket P/N. 345-72227-0 P/N. 345-72228-0 P/N. 346-72231-0 P/N. 346-72232-0 Removing spring pin Installing spring pin Removing and installing bevel gear B nut ø79.5 x ø51.5 Thickness Gauge Center Plate...
Page 233 Universal Puller Plate Bevel Gear Bearing Installation Tool Slide Hammer Kit Roller Bearing Press Kit P/N. 3AC-99750-0 P/N. 346-72719-0 P/N. 3AC-99080-0 P/N. 3AC-72900-3 Bevel Gear Assy A Bevel Gear Assy A Installing and removing Removing bearing Installing bearing Removing bearing outer race gear case roller bearing 4st 25/30 2022...
Page 234: Parts Layout
Lower Unit 2. Parts Layout Gear Case (Drive Shaft) Fig.10-9 5 N·m (4 lb·ft) [0.5 kgf·m] 5 N·m (4 lb·ft) [0.5 kgf·m] 35 N·m (25 lb·ft) [3.5 kgf·m] 19 N·m (14 lb·ft) [1.9 kgf·m] 4st 25/30 2022...
Page 235 Ref. Part Name Q'ty Remarks Gear Case Assy Roller Bearing Plug Gasket Do not reuse. Trim Tab Bolt Water Strainer Screw Water Strainer Screw Nylon Nut Bevel Gear B Drive Shaft Spring Guide Drive Shaft Spring 16-1 Drive Shaft (S) 16-2 Drive Shaft (L) 16-3...
Page 236 Lower Unit Fig.10-9 5 N·m (4 lb·ft) [0.5 kgf·m] 5 N·m (4 lb·ft) [0.5 kgf·m] 35 N·m (25 lb·ft) [3.5 kgf·m] 19 N·m (14 lb·ft) [1.9 kgf·m] 4st 25/30 2022...
Page 237 Ref. Part Name Q'ty Remarks 41-1 Water Pipe (S) 41-2 Water Pipe (L) 41-3 Water Pipe (UL) Water Pipe Seal (Lower) Bolt Washer 4st 25/30 2022...
Page 238: Gear Case (Propeller Shaft)
Lower Unit Gear Case (Propeller Shaft) 35 N·m (25 lb·ft) [3.5 kgf·m] 4st 25/30 2022...
Page 239 Ref. Part Name Q'ty Remarks Tapered Roller Bearing 30205 Shim 26.5-34.8-0.1 Shim 26.5-34.8-0.15 Bevel Gear Assy (A) Push Rod Ball 3/8 Spring Retainer Snap Clutch Spring Propeller Shaft Washer Bevel Gear C 18-24-1.5 Bevel Gear C Propeller Shaft Housing Assy O-ring 3-62.5 Do not reuse.
Page 240: Inspection Items
Lower Unit 3. Inspection Items 1) Draining Gear Oil Drain the gear oil. Refer to “Replacement of Gear Oil” in Chapter 3. • Drain all gear oil, and check for metal particles in the drained oil. • Check the gear oil color. A white or cream color may indicate that the gear oil is contaminated by water.
Page 241: Removal Of Lower Unit
3) Removal of Lower Unit WARNING When working with the outboard motor in the tilt up position, be sure to lock it with the tilt stopper. • Removal of the lower unit does not require the power unit to be removed from the outboard motor.
Page 242: Removal Of Water Pump And Cam Rod
Lower Unit 4) Removal of Water Pump and Cam Rod Loosen the installation bolts in the pump case (upper), and remove the pump case (upper) 1-2-3-4. Remove the water pump impeller key 5. Loosen the installation bolt in the pump case (lower) and remove the pump case gasket 6, guide plate 7, guide plate gasket 8, and pump case (lower) 9.
Page 243: Inspection Of Water Pump
Remove the cam rod 0. 5) Inspection of Water Pump Check the pump case liner 1 and guide plate 2 for deformation and wear. Replace if necessary. Check the pump impeller 3 for cracks, damage, and wear. Replace if necessary. •...
Page 244: Disassembly Of Water Pump Case (Lower)
Lower Unit 7) Disassembly of Water Pump Case (Lower) Remove the oil seal. Be careful not to damage the oil seal press fit surface. Do not reuse. 8) Assembly of Water Pump Case (Lower) Install and press fit the oil seal 1 by pressing. •...
Page 245: Inspection Of Clutch Cam
10) Inspection of Clutch Cam Check the part for wear and damage. Replace if necessary. Check especially for wear on the surface a that contacts the clutch push rod and flaws on the circumference b. 11) Assembly of Clutch Cam Attach the clutch cam 2 to the cam rod 1.
Page 246: Removal Of Propeller Shaft Housing Assy
Lower Unit 12) Removal of Propeller Shaft Housing Assy Remove the propeller shaft assy. Use a plastic hammer to remove the assy if it cannot be removed by inserting a flathead screwdriver or the like. Hold the propeller shaft and fully pull out the propeller shaft housing assy.
Page 247 Use a commercially available bearing puller to remove the ball bearing. Before removal, check the bearing for play or deflection. Replace if necessary. Do not reuse. Remove the oil seal 1. Do not scratch the housing when removing the oil seal.
Page 248: Inspection Of Propeller Shaft Housing
Lower Unit 14) Inspection of Propeller Shaft Housing Clean the propeller shaft housing, and check it for cracks or damage. Replace if necessary. Check the teeth and dog sections of the bevel gear C for cracks and abnormal wear. Replace if necessary. Check the bearing for abnormalities.
Page 249 Install the oil seal 1. Driver Rod 2: P/N. 3AC-99702-0 Oil Seal Attachment 3: P/N. 3AD-99820-0 • Install the oil seal with the mark facing the tool side. • Clean the oil seal installation face and apply gear oil before installation. 27.5 mm •...
Page 250 Lower Unit Install the ball bearing 4. Use the C gear bearing press tool 5 to assemble a new 51.5 mm bearing to the propeller shaft housing. • Clean the bearing installation surface and apply gear oil before installation. • Install the bearing with the mark facing the tool side.
Page 251: Disassembly Of Propeller Shaft Assy
16) Disassembly of Propeller Shaft Assy Remove the push rod 1 and ball 2. Insert a flathead screwdriver into one end of the clutch pin snap 3, and remove the snap from the clutch groove while winding it. 3 Clutch Pin Snap Do not reuse.
Page 252: Inspection Of Propeller Shaft Assy
Lower Unit 17) Inspection of Propeller Shaft Assy Check the propeller shaft for bends, wear, and damage. Replace if necessary. Measure the propeller shaft runout. Runout Limit: 0.05 mm (0.0020 in) a Support Points Check the clutch dogs b and push rod c for cracks and wear.
Page 253: Assembly Of Propeller Shaft Assy
18) Assembly of Propeller Shaft Assy Attach the spring 1, spring retainer 2, push rod 3, ball 4, clutch 5, and clutch pin 6 to the propeller shaft. • Attach the clutch with the groove side a facing the push rod side. •...
Page 254: Removal Of Bevel Gear Assy A
Lower Unit 19) Removal of Bevel Gear Assy A Place your hand inside the gear case and remove the bearing 1 and bevel gear assembly A 2. • The bevel gear assy A can be removed by pinching the assy in the gear case with your fingers and pulling it out from your thumb side while lifting it up slightly.
Page 255: Inspection Of Bevel Gear Assy A
21) Inspection of Bevel Gear Assy A Check the bevel gear assy A teeth and clutch claws for cracks, damage, or wear. Replace if necessary. 22) Assembly of Bevel Gear Assy A Install the shim 1 removed during disassembly and install the taper roller bearing 2 using a press.
Page 256: Removal Of Drive Shaft
Lower Unit 23) Removal of Drive Shaft Remove the bevel gear B nut 1 , and remove the bevel gear B 2 and drive shaft. • Degrease the bevel gear B nut completely so that the nut wrench does not slip on the nut. •...
Page 257: Disassembly Of Drive Shaft
24) Disassembly of Drive Shaft Remove the shim 1 and outer race 2 . Remove the drive shaft spring 3. Use the universal puller plate 4 to remove the taper roller bearing 5 with a press. CAUTION Do not reuse the removed bearing. Be sure to replace it with a new one.
Page 258: Inspection Of Bevel Gear B
Lower Unit 26) Inspection of Bevel Gear B Check the teeth and spline of the bevel gear B for cracks, damage, and wear. Replace if necessary. 27) Assembly of Drive Shaft Use a press and an appropriate pipe to install the taper roller bearing 1 .
Page 259: Disassembly Of Gear Case
28) Disassembly of Gear Case Use the tools below to remove the roller bearing 1. Roller Bearing Press Kit: P/N. 3AC-72900-3 Roller Bearing Outer Press Flange 2: P/N. 3AC-72900-2 Roller Bearing Outer Press Guide 3: P/N. 3AC-72765-2 Roller Bearing Press Rod 4: P/N.
Page 260: Inspection Of Gear Case
Lower Unit 29) Inspection of Gear Case Check the skeg a and torpedo-like area b for cracks and other damage. Replace if necessary. 30) Assembly of Gear Case CAUTION When the gear case, bevel gear assy A gear, or bearing is replaced, measure the backlash and select and install a proper shim.
Page 261 Install the roller bearing 4 using the tools below. Roller Bearing Press Kit: P/N. 3AC-72900-3 Roller Bearing Outer Press Flange 5: P/N. 3AC-72900-2 Roller Bearing Outer Press Guide 6: P/N. 3AC-72765-2 Roller Bearing Press Rod 7: P/N. 3RS-72769-0 Roller Bearing Press 8: P/N.
Page 262: Assembly Of Bevel Gear B
Lower Unit 31) Assembly of Bevel Gear B Install the drive shaft spring guide 1 and drive shaft 2 . Apply gear oil to the bearing section of the drive shaft. GEAR GEAR GEAR Install the bevel gear B 3 and tighten the bevel gear B nut 4 to the specified torque.
Page 263: Bevel Gear B Height Measurement And Shim Selection
32) Bevel Gear B Height Measurement and Shim Selection CAUTION When the gear case, drive shaft, or oil seal housing assy is replaced, measure the height of bevel gear B and the backlash between the gears and adjust the shim. When measuring the backlash of each gear, first measure the height of the bevel gear B of the drive shaft, then adjust the value accordingly.
Page 264 Lower Unit 4 Bearing Outer Race Add and adjust the shim 5 to the lower side of the pump case lower 1 so that the gap a is within the specified range. Bevel Gear B Height a: 0.60 - 0.64 mm (0.0236 - 0.0252 in) Type of Shim Thickness Part No.
Page 265: Backlash Measurement Between Bevel Gear Assy A And Bevel Gear B And Shim Selection
33) Backlash Measurement Between Bevel Gear Assy A and Bevel Gear B and Shim Selection Backlash Measuring Tool Kit: P/N. 3C8-72234-2 Measuring Tool Set Piece 3: P/N. 346-72245-1 Backlash Measuring Tool Clamp 9: P/N. 3B7-72720-0 Dial Gauge Plate 8: P/N. 3B7-72729-0 Install the pump case (lower) following the procedure in Chapter 6, “Assembly of Lower Unit."...
Page 266 Lower Unit Perform shim adjustment as necessary based on the Adjusting shim amount Gauge value (mm) gauge value obtained. The table shows the relation (mm) between dial gauge readings and shim adjustments. 0.00 - 0.13 -0.1 1. Values in this table indicate dial gauge 0.14 - 0.34 -0.05 readings obtained when using the special tool.
Page 267: Installation Of Pump Case
34) Installation of Pump Case Install the adjusted shim 1. Install the O-ring 2, cam rod 3, and bolts 4 to the pump case (lower). • Apply OBM grease to the O-ring of the pump case (lower). • Pay attention to the orientation of the cam rod. •...
Page 268: Installation Of Propeller Shaft Housing Assy
Lower Unit Insert and install the pump case (upper) y and gasket (one) into the pump case (lower) 6 from the upper end of the drive shaft. CAUTION When installing the pump case (upper) y , install the case while turning the drive shaft w clockwise so that the impeller blades are not reverse to the direction of engine rotation.
Page 269: Inspection Of Gear Case (For Leakage)
36) Inspection of Gear Case (for Leakage) Drain the gear oil. Remove the upper oil plug 1 and connect a commercially available leakage tester to the hole. Apply the specified pressure to the gear case, and check if the pressure is maintained for 10 seconds. CAUTION Do not apply pressure to the gear case over the specified value.
Page 270: Installation Of Lower Unit
Lower Unit 37) Installation of Lower Unit Tilt up the outboard motor and lock it with the tilt stopper. Set the shift rod 1 to the up position (forward position). • Apply a thin coat of TEFLON grease to the spline of the drive shaft before installation.
Page 271 Install the shift rod joint, and connect the shift rod using a new spring pin. • Double-check that the shift rod is fully raised. In addition, check that the shift lever is in the forward (F) position. (Shift lever is in contact with stopper) If the joint is not tightened in the correct position, shifting in and out may become...
Page 272 Lower Unit Attach the propeller and tighten the propeller nut 4 to the specified torque. CAUTION • Before removing or installing the propeller, be sure to disconnect the battery cables from the battery and remove the stop switch lock plate. •...
Page 273 Bracket 1. PT Wiring Diagram and Layout ……… 7-2 11) Installation of Clamp Bracket 2. Parts Layout ……………………………… 7-4 (Power Tilt Model, Gas Assist Model) … 7-38 Drive Shaft Housing ………………………… 7-4 12) Disassembly of Clamp Bracket Bracket (Manual Tilt) ………………………… 7-6 (Manual Tilt Model) ………………………...
Page 274: Wiring Diagram And Layout
Bracket 1. PT Wiring Diagram and Layout Battery PT Solenoid Switch (UP) Switch Wiring Colors R : Red B : Black PT Solenoid Sb : Sky Blue Switch (DN) P : Pink L : Blue G : Green Circuit Breaker PT Motor Tilt Cylinder Shock Blow Valve...
Page 275 4st 25/30 2022...
Page 276: Parts Layout
Bracket 2. Parts Layout Drive Shaft Housing 24 N·m (18 lb·ft) [2.4 kgf·m] Fig.13-39 Fig.13-38 Fig.11-39 Fig.11-39 1 15 N·m (11 lb·ft) [1.5 kgf·m] 2 30 N·m (22 lb·ft) [3.0 kgf·m] 19 N·m (14 lb·ft) [1.9 kgf·m] 4st 25/30 2022...
Page 277 Ref. Part Name Q'ty Remarks Drive Shaft Housing Assy (S) Drive Shaft Housing Assy (S) Drive Shaft Housing Assy (L) Drive Shaft Housing Assy (L) Oil Seal Do not reuse. Dowel Pin 6-16 Drain Bolt Washer Do not reuse. Flushing Connector Cap Seal Ring Engine Basement Seal Bolt...
Page 278: Bracket (Manual Tilt)
Bracket Bracket (Manual Tilt) 5 N·m (4 lb·ft) [0.5 kgf·m] Fig.19-21 27 N·m (20 lb·ft) [2.7 kgf·m] 24 N·m (18 lb·ft) [2.4 kgf·m] 71 72 27 N·m (20 lb·ft) [2.7 kgf·m] 38 39 27 N·m (20 lb·ft) [2.7 kgf·m] 4st 25/30 2022...
Page 279 Ref. Part Name Q'ty Remarks Clamp Bracket (R) Clamp Bracket (L) Anode Bolt Co-Pilot Decal Swivel Bracket Shaft Assy Cap Nut Bushing Nylon Nut 7/8-14 Distance Piece Washer Thrust Rod Thrust Rod Spring Swivel Bracket Assy Grease Fitting Nylon Nut 8-P1.25 Washer Friction Lever Washer 8.1-20-0.8...
Page 280 Bracket 5 N·m (4 lb·ft) [0.5 kgf·m] Fig.19-21 27 N·m (20 lb·ft) [2.7 kgf·m] 24 N·m (18 lb·ft) [2.4 kgf·m] 71 72 27 N·m (20 lb·ft) [2.7 kgf·m] 38 39 27 N·m (20 lb·ft) [2.7 kgf·m] 4st 25/30 2022...
Page 281 Ref. Part Name Q'ty Remarks Bolt Damper (Upper) Carrying Handle Tilt Stopper Spring Pin Bushing 10.2-12-29.5 Setting Plate Bolt Setting Piece Friction Spring Anode Bolt Reverse Lock Arm Reverse Lock Rod Split Pin 2-12 Reverse Lock Shoulder Bolt Reverse Lock Spring (L) Washer 6-16-1.5 Reverse Lock Lever Reverse Lock Link...
Page 282: Bracket (Pt · Gas Assist)
Bracket Bracket (PT · Gas Assist) Fig.13 Fig.13 11 N·m (8 lb·ft) [1.1 kgf·m] Fig.13-9 Fig.13 GAS ASSIST 7-10 4st 25/30 2022...
Page 283 Ref. Part Name Q'ty Remarks Clamp Bracket (PTT-R) Clamp Bracket (PTT-L) Swivel Bracket Shaft Assy Bushing PTT Thrust Rod Snap Pin Swivel Bracket Assy Collar 10.2-12-12 Tilt Stopper Spring 10-1 Tilt Stopper Kit For PT model 10-2 Tilt Stopper Kit For Gas assist model Tilt Stopper Grip Spring Pin 3.5-16...
Page 284: Power Tilt
Bracket Power Tilt 35 N·m (25 lb·ft) [3.5 kgf·m] 155 N·m (112 lb·ft) [15.5 kgf·m] 4.5 N·m (3.3 lb·ft) [0.46 kgf·m] 1.5 N·m (1.1 lb·ft) [0.15 kgf·m] Chamfered 2.5 N·m (1.8 lb·ft) [0.25 kgf·m] 5 N·m (4 lb·ft) [0.5 kgf·m] 1.8 N·m (1.4 lb·ft) [0.18 kgf·m] 7-12 4st 25/30 2022...
Page 285 Ref. Part Name Q'ty Remarks Manual Valve Assy Seal Set O-ring 2.4-9.8 Do not reuse. C-ring Do not reuse. Joint Dust Seal O-ring 2.4-12.3 Do not reuse. Cylinder Inner Tube Piston Rod Assy O-ring 2-28.5 Do not reuse. Free Piston Back-Up Ring O-ring 2.4-27.7 Do not reuse.
Page 286: Tiller Handle
Bracket Tiller Handle Fig.18-1 42.5 N·m (31.4 lb·ft) [4.34 kgf·m] for MF for EF 7-14 4st 25/30 2022...
Page 287 Ref. Part Name Q'ty Remarks Tiller Handle Assy Plastic Rivet 6.5 Stud Grip Throttle Shaft Throttle Shaft Damper Bushing 14-15.8-7 Screw Throttle Shaft Support Screw Friction Piece Adjusting Nut Spring Bolt Bracket Screw Stop Switch Decal Throttle Decal Tiller Handle Cover Grommet 17-2.7 Main Switch Assy Grommet...
Page 288 Bracket Fig.18-1 42.5 N·m (31.4 lb·ft) [4.34 kgf·m] for MF for EF 7-16 4st 25/30 2022...
Page 289 Ref. Part Name Q'ty Remarks Collar 6.5-10.5-10 Washer 6.5-21-1 Bolt Shift Lever Rod Washer Wave Washer Protector Washer 6.5-30-1 7-17 4st 25/30 2022...
Page 290: Multi-Function Tiller Handle
Bracket Multi-Function Tiller Handle 25 N·m (18 lb·ft) [2.5 kgf·m] 27 N·m (20 lb·ft) [2.7 kgf·m] 26 N·m (19.5 lb·ft) [2.7 kgf·m] 45 N·m (34.6 lb·ft) [4.5 kgf·m] 5 N·m (4 lb·ft) [0.5 kgf·m] 7-18 4st 25/30 2022...
Page 291 Ref. Part Name Q'ty Remarks Tiller Handle Kit Throttle Wire Shift Cable Stop Switch Assy Stop Switch Lanyard Assy Main Switch Assy Main Switch Key No.943 Main Switch Key No.944 Main Switch Key No.945 Main Switch Key Covering Cap Main Switch Cap (Waterproof) Grommet Throttle Decal Shift Decal...
Page 292 Bracket 25 N·m (18 lb·ft) [2.5 kgf·m] 27 N·m (20 lb·ft) [2.7 kgf·m] 26 N·m (19.5 lb·ft) [2.7 kgf·m] 45 N·m (34.6 lb·ft) [4.5 kgf·m] 5 N·m (4 lb·ft) [0.5 kgf·m] 7-20 4st 25/30 2022...
Page 293 Ref. Part Name Q'ty Remarks Bolt Friction Lever Bolt Friction Lever Bracket Disc Nylon Nut 8-P1.25 Washer Cap Nut Washer 8.1-20-0,8 7-21 4st 25/30 2022...
Page 294: Bottom Cowl
Bracket Bottom Cowl MF/EF/E MODEL Fig.6-45 7-22 4st 25/30 2022...
Page 295 Ref. Part Name Q'ty Remarks Bottom Cowl Mount 8.5-14-2.5 Spacer 6.2-9-15.7 Bolt Washer 6.5-21-1 Nipple Pilot Lamp Assy Gasket PTT Switch Assy Bracket Bolt Grommet PTT Switch Assy Remote Cont Cable Stay Cover Bolt Cowl Latch Assy Bolt Washer 6.5-23-1.5 Grommet Grommet 40-18-3 Cable Terminal Holder Cover...
Page 296: Shift
Bracket Shift 3.5 N·m (2.5 lb·ft) [0.3 kgf·m] Fig.16-49 7-24 4st 25/30 2022...
Page 297 Ref. Part Name Q'ty Remarks Shift Lever Shaft Assy Neutral Switch Neutral Switch Actuator Neutral Switch Bracket Bolt Holder Bolt Holder Bolt Shift Detent Spring Shift Detent Supporter Bolt Throttle Drum Assy Bolt Washer 6-16-1.5 Collar 6.5-10.5-9.3 Throttle Wire Bracket Bolt Link Rod Assy (Throttle) Snap Pin d=6...
Page 298: Remote Control
Bracket Remote Control Fig.13-26 Fig.18-14 Fig.18-16 Fig.18-1 7-26 4st 25/30 2022...
Page 299 Ref. Part Name Q'ty Remarks Shift Lever Rod Washer 8.5-19-1,6 Snap Pin d=8 Shift Arm Cable Joint Shift Arm Bracket Bolt Bolt Washer 6.5-21-1 Collar 6.5-10.5-9.3 Link Rod Assy (Throttle) Throttle Arm Washer 6.5-21-1 Snap Pin d=8 Drag Link Assy Nylon Nut 3/8-24UNF Washer 9.6-18-2 Seal Ring...
Page 300: Inspection Items
Bracket 3. Inspection Items 1) Inspection of Throttle Cable and Shift Cable Check the operation of the throttle cable and shift cable. Remove the tiller handle cover and check the cable inner wire and outer wire for bending or damage. Replace if necessary.
Page 301: Adjustment Of Friction Lever
Install the cable 9 of the inner wire b that stretches when the throttle grip is set to the fully closed position. Next, install the other cable 0 (of the inner wire b that stretches when the throttle grip is set to the fully open position).
Page 302: Removal Of Drive Shaft Housing
Bracket 4) Removal of Drive Shaft Housing Prepare a waste oil receptacle under the drain hole, remove the drain bolt, and drain the oil completely. Refer to Chapter 3. Remove the bolt 1 and remove the bolt cover 2. Remove the lower mount nut 3 and bolt 4. Remove the upper rubber mount nuts 5.
Page 303: Disassembly Of Drive Shaft Housing
5) Disassembly of Drive Shaft Housing Remove the upper rubber mount installation bolts 1 and remove the rubber mounts 2 and the dampers 3 from the drive shaft housing. Check the rubber mounts 2 and dampers 3 for abnormalities such as cracks and fissures. Replace if any abnormality is found.
Page 304: Assembly Of Drive Shaft Housing
Bracket Remove the bolt 7, and then remove the water pipe 8 from the drive shaft housing. Check the water pipe seal 9 for abnormalities such as cracks. 6) Assembly of Drive Shaft Housing Install the water pipe seal 1 onto the water pipe, and the assembly into the drive shaft housing.
Page 305: Installation Of Drive Shaft Housing Assy
Install the upper rubber mounts 6 and dampers 7 onto the drive shaft housing and tighten the bolts 8. Install the dampers in the orientations shown in the diagram. Upper Rubber Mount Bolt: 13 N · m (9 lb · ft) [1.3 kgf · m] 7) Installation of Drive Shaft Housing Assy Attach the damper 2 to the lower rubber mount 1, then attach the drive shaft housing to the clamp bracket assy.
Page 306: Removal Of Steering Shaft
Bracket Install the bolt cover 6. 8) Removal of Steering Shaft Remove the drive shaft housing assy by referring to Chapter 7, “Removal of Drive Shaft Housing.” Remove the mount bracket 1 and lower rubber mount 2. Remove the friction plate bolts 3. (Basic Tiller Handle / Multi-Function Tiller Handle Models only) 7-34 4st 25/30 2022...
Page 307: Installation Of Steering Shaft
Pull out the steering shaft 4 from the swivel bracket assy to remove. Remove the washer and then remove the O-ring and collar from the steering bracket. Check the individual parts. 9) Installation of Steering Shaft Attach the thrust plate 1 and bushing 2 to the steering shaft.
Page 308: Disassembly Of Clamp Bracket (Power Tilt Model, Gas Assist Model)
Bracket Pour OBM grease into the bushing a through the grease nipple 8 until it overflows. A Manual Tilt Model B Power Tilt Model, Gas Assist Model Install the friction plate bolts 9 and adjust the friction lever. (Basic Tiller Handle / Multi-Function Tiller Handle Models only) Apply screw locking agent (ThreeBond 1342) to the thread area of the friction plate bolts.
Page 309 7-37 4st 25/30 2022...
Page 310: Installation Of Clamp Bracket (Power Tilt Model, Gas Assist Model)
Bracket 11) Installation of Clamp Bracket (Power Tilt Model, Gas Assist Model) Install the clamp bracket in the reverse order of removal. Nylon Nut: 24 N · m (17 lb · ft) [2.4 kgf · m] Pour grease into the bushings a through the grease nipples 1 until it overflows.
Page 311: Installation Of Clamp Bracket (Manual Tilt Model)
Check the swivel bracket shaft and other parts for abnormality, and replace if necessary. 13) Installation of Clamp Bracket (Manual Tilt Model) Install the clamp bracket in the reverse order of removal. Nylon Nut 1: 24 N · m (17 lb · ft) [2.4 kgf · m] Distance piece nut 2: 6 N ·...
Page 312: Removal Of Pt Unit / Gas Shock Absorber
Bracket 14) Removal of PT Unit / Gas Shock Absorber Fully tilt up the outboard motor and lock it with the tilt stopper 1. WARNING • Leaving the outboard motor up without locking may lead to accidental descent due to the reduction of PT unit hydraulic pressure.
Page 313: Removal Of Pt Motor
15) Removal of PT Motor Remove the reserve tank 2, PT motor 3, and O-rings 4 and 5 from the PT unit 1. CAUTION • When removing the PT motor (reserve tank), the tilt rod should be fully extended to prevent fluid from spurting out due to internal pressure.
Page 314: Inspection Of Pt Motor
Bracket 16) Inspection of PT Motor Measure the length of the brush. Replace the motor assy if the specified value or less. Brush Wear Limit a: 6 mm ( 0.236 in) Check the electrical conductivity of the brush and circuit breaker.
Page 315: Assembly Of Pt Motor
17) Assembly of PT Motor Unlock the brush spring, push the brushes into the brush holders, and install the armature. Lock the brush spring. Check the O-ring and replace if necessary. Install the yoke assy to the motor base. Cover the end of the armature shaft with a clean cloth, hold the shaft with a pair of pliers, and carefully install the armature so that it does not get detached from the brushes.
Page 316: Removal Of Pt Pump And Valve
Bracket 18) Removal of PT Pump and Valve CAUTION • When removing the PT motor (reserve t a n k ) , t h e t i l t r o d s h o u l d b e f u l l y extended to prevent fluid from spurting out due to internal pressure.
Page 317: Removal Of Tilt Cylinder
20) Removal of Tilt Cylinder Retract the tilt rod. Sandwich the PT unit 1 from both sides with wood or aluminum plates a and secure with a vice. Secure the joint 2, loosen the nut 3 with a wrench, and remove the joint 2 and nut 3.
Page 318: Inspection Of Valve
Bracket 22) Inspection of Valve Check the check valve and valve of the tilt rod assy 1 for dirt or deposits. Clean if necessary. 23) Installation of PT Pump and Motor Sandwich the PT unit 1 from both sides with wood or aluminum plates and secure with a vice.
Page 319: Assembly Of Tilt Cylinder
Install new O-rings 6 and 7, the coupling 8, PT motor assembly 9, and reserve tank 0, and tighten the bolt q to the specified torque. Reserve Tank Bolt: 4.5 N · m (3.3 lb · ft) [0.46 kgf · m] 24) Assembly of Tilt Cylinder Install a new O-ring 1 to the tilt cylinder 2.
Page 320 Bracket Refill the PT fluid to the first level from the bottom of the tilt cylinder installation area. Recommended PT Fluid: ATF DEXRON III Insert the assembly of the tilt cylinder 1, tilt rod 5, inner tube 8, free piston 4, and O-ring into the PT unit 9. Install the tilt cylinder 1 and tighten to the specified torque.
Page 321: Installation Of Pt Unit / Gas Shock Absorber
25) Installation of PT Unit / Gas Shock Absorber Fully tilt up the outboard motor and lock it with the tilt stopper 1. WARNING • Be sure to lock the outboard motor with the tilt stopper after it is tilted up. Leaving the outboard motor up without locking may lead to accidental descent due to the reduction of PT unit hydraulic...
Page 322: Air-Purging Of Pt Unit (With Outboard Motor Installed)
Bracket 26) Air-Purging of PT Unit (With Outboard Motor Installed) Fully tilt up the outboard motor and lock it with the tilt stopper 1. Remove the cap 2 and check the amount of fluid in the reserve tank. Turn the manual valve counterclockwise until it is full. Manually tilt up the outboard motor until it is full and lower it under its own weight.
Page 323: Inspection Of Pt Solenoid
If the amount of PT fluid is insufficient, replenish the PT fluid to the specified level. Recommended PT Fluid: ATF DEXRON III Install the reserve tank cap and tighten to the specified torque. Reserve Tank Cap: 1.5 N·m (1.1 lb·ft ) [0.15 kgf·m] Repeat steps 5 through 12 until the PT fluid reaches the specified level.
Page 324 Bracket 7-52 4st 25/30 2022...
Page 325 Electrical System 1. Special Tools ……………………………… 8-2 10) Inspection of the Start Switch (EF, EFT) … 8-25 2. Electrical Component Layout ……… 8-3 11) Inspection of the Main (Key) Switch …… 8-25 Port Side View ……………………………… 8-3 12) Inspection of the Stop Switch Bow Side View ………………………………...
Page 326: Special Tools
Electrical System 1. Special Tools Vacuum/Pressure Gauge Spark Tester P/N. 3AC-99020-1 P/N. 3F3-72540-0 Inspecting pressure Inspecting ignition 4st 25/30 2022...
Page 327: Electrical Component Layout
2. Electrical Component Layout Port Side View 1 Fuse (20A) (except for MF model) 2 Starter solenoid (except for MF model) 3 ECU 4 PT relay (UP Side) (EFT, EPT) 5 PT relay (DOWN Side) (EFT, EPT) 6 Engine temperature sensor 7 Ignition coil 8 Oil pressure switch 9 Rectifier (except for MF model)
Page 328: Bow Side View
Electrical System Bow Side View 1 Pulser coil 2 Exciter coil/charge coil (charge coil except for MF model) 3 Throttle position sensor 4 Starter motor (except for MF model) 4st 25/30 2022...
Page 329: Starboard Side View
Starboard Side View 1 Fuel injector 2 ISC valve 3 T-MAP sensor 4 Neutral switch (except for MF model) 5 Vapor separator 4st 25/30 2022...
Page 330: Housing Cover (Front)
Electrical System Housing Cover (Front) 1 Warning lamp 2 Main switch 3 Stop switch 1 Stop switch 2 Start switch (for EF, EFT model) 3 Trolling control switch 4 PT switch (for EFT model) 4st 25/30 2022...
Page 331 4st 25/30 2022...
Page 332: Parts Layout
Electrical System 3. Parts Layout Magneto 70 N·m (52 lb·ft) [7.0 kgf·m] EF/E/ET Fig.9-48 Fig.9-31 Fig.9-48 Fig.9-31 4st 25/30 2022...
Page 333 Ref. Parts Name Q'ty Remarks Flywheel W/Gear Alternator Assy Alternator Assy Key 13.4-5-4 Bolt Washer 13-26-3.2 Bolt Starter Pulley Bolt Coil Bracket Bolt Pulsar Coil Pulsar Coil Bolt Starter Lock Cable Bracket Bolt Cable Terminal Holder Bolt Fuse Holder Bracket Screw Bracket Bolt...
Page 334: Electrical Parts
Electrical System Electrical Parts Fig.1-31 8 N·m (6 lb·ft) [0.8 kgf·m] Fig.8-34 43 42 8-10 4st 25/30 2022...
Page 335 Ref. Parts Name Q'ty Remarks Oil Pressure Switch Rectifier Complete Cover Bolt Bolt Starter Motor Assy Pinion Assy Washer Brush Holder Assy Screw Bushing 2 O-ring Do not reuse. Bushing 1 Washer Spring Washer Bolt Spring Washer Washer Bolt Starter Motor Band Damper Bolt Battery Cable L=2500...
Page 336 Electrical System Fig.1-31 8 N·m (6 lb·ft) [0.8 kgf·m] Fig.8-34 43 42 8-12 4st 25/30 2022...
Page 337 Ref. Parts Name Q'ty Remarks Bolt Washer 6-16-1.5 Rubber Mount Collar Plate Bolt Plate Band Engine Temp Sensor 51-1 ECU Assy (25DO) 51-2 ECU Assy (30DO) 51-3 ECU Assy (25) 51-4 ECU Assy (30) Bolt Washer 6-16-1.5 Spacer 6.2-9-27 Bolt Band Do not reuse.
Page 338: Intake Manifold
Electrical System Intake Manifold 6.0 N·m (4.4 lb·ft) [0.6 kgf·m] 2.5 N·m (2 lb·ft) [0.25 kgf·m] 2.5 N·m (2 lb·ft) [0.25 kgf·m] 24 25 Fig.5-1 5.5 N·m (4.0 lb·ft) [0.55 kgf·m] Fig.7-23 Fig.7-23 Fig.6-1 Fig.7-23 Fig.3-43 9.0 N·m (6.6 lb·ft) [0.9 kgf·m] Fig.10-16 8-14 4st 25/30 2022...
Page 339 Ref. Parts Name Q'ty Remarks Intake Manifold Gasket Do not reuse. Throttle Body Assy Bolt Gasket Do not reuse. Intake Silencer Assy Bolt Fuel Rail O-ring 1.9-9.8 Do not reuse. Valve Assy (Pressure Check) Nipple Holding Plate Bolt Fuel Injector Assy Seal Ring Do not reuse.
Page 340: Fuel System
Electrical System Fuel System Fig.5-31 Fig.5-30 Fig.5-1 Fig.17-6 Fig.10-1 35 36 Fig.17-26 Fig.17-1 8-16 4st 25/30 2022...
Page 341 Ref. Parts Name Q'ty Remarks Vapor Separator Assy Cover Seal Screw Drain Screw Gasket Do not reuse. Float Valve Assy Float Arm Pin Float Grommet Filter (Inlet) Holder Fuel Feed Pump O-ring Do not reuse. O-ring Do not reuse. O-ring Do not reuse.
Page 342 Electrical System Fig.5-31 Fig.5-30 Fig.5-1 Fig.17-6 Fig.10-1 35 36 Fig.17-26 Fig.17-1 8-18 4st 25/30 2022...
Page 343 Ref. Parts Name Q'ty Remarks 43-1 Fuel Hose W/Protector 43-2 Fuel Hose W/Protector Water Hose Water Hose 46-1 Fuel Hose W/Protector 46-2 Fuel Hose W/Protector Fuel Hose W/Protector Adapter Cord L=200 52-1 Fuel Hose W/Protector 52-2 Fuel Hose W/Protector Fuel Hose Joint Plug Band Do not reuse.
Page 344: The Ignition System And The Ignition Control System
Electrical System 4. The Ignition System and the Ignition Control System 1) Inspection of the Ignition Spark WARNING • When testing, install the electrode cap p ro p e r l y s o a s t o p re v e n t l e a k s a n d contact with the wiring of the spark tester, and perform the test carefully.
Page 345: Inspection Of The Ignition Coil
3) Inspection of the Ignition Coil Disconnect the ignition coil coupler. Measure the ignition coil resistance. Replace it if the value is not as specified. This test can be conducted without removing the part. Ignition Coil Resistance: Primary coil: between White (W) and Black (B) Secondary coil: between high tension cable and Black (B) Secondary coil: between plug cap and Black (B)
Page 346: Inspection Of The Pulser Coils
Electrical System 5) Inspection of the Pulser Coils Disconnect the #1 pulser coil connector 1 on the starboard side. Measure the resistance of the #1 pulser coil. Replace it if the value is not as specified. Disconnect the #2 pulser coil coupler 2 (1 pin) on the port side and test the #2 pulser coil in the same way as #1.
Page 347: Inspection Of The Oil Pressure Switch
7) Inspection of the Oil Pressure Switch Remove the part to test it as a separate unit. Remove the oil pressure switch 1. Check the conductivity of the oil pressure switch. Replace it if it is not conductive. Connect the vacuum/pressure gauge to the oil pressure switch.
Page 348: Inspection Of The Engine Temperature Sensor
Electrical System 8) Inspection of the Engine Temperature Sensor Remove the part to test it as a separate unit. Remove the engine temperature sensor 1 from the engine. Place the engine temperature sensor in a vessel containing water and slowly heat the water. To measure the resistance at low temperatures, place the sensor in ice water, refrigerator, etc.
Page 349: Inspection Of The Start Switch (Ef, Eft)
10) Inspection of the Start Switch (EF, EFT) Check the electrical conductivity of the start switch and replace it if it is not conductive. This test can be conducted without removing the part. Lead Wire Color Switch Position Green (G) Red (R) Free: OFF Pushed: ON...
Page 350: Inspection Of The Stop Switch (Except For Mf)
Electrical System 12) Inspection of the Stop Switch (Except for MF) Check the conductivity of the stop switch and replace it if it is not conductive. Lead Wire Color Switch Position Brown (Br) Black (B) Remove lock a Install lock b Press switch c 8-26 4st 25/30 2022...
Page 351: The Fuel Control System
5. The Fuel Control System 1) Inspection of the Injector Measure the injector resistance. • This test can be conducted without removing the part. • The injector operation test can be conducted using the "Engine Shut-down Test" or "Engine Running Test" of the diagnosis system. Injector Resistance (Reference Value): (at 25°C) 2) Inspection of the ISC Valve Measure the resistance between the ISC valve terminals...
Page 352: Inspection Of The T-Map Sensor
Electrical System 3) Inspection of the T-MAP Sensor The MAP (manifold pressure) sensor and MAT (intake air temperature) sensor are integrated in this sensor. Inspection of the MAT Sensor Measure the ambient temperature. Connect a computer to the outboard motor and use the diagnosis system to display "Air Temperature (Intake Air Temperature)."...
Page 353: Inspection Of The Throttle Position Sensor (Tps)
5) Inspection of the Throttle Position Sensor (TPS) Check the throttle position sensor resistance. Replace the entire throttle body if the value is not as specified. Resistance Between Terminals: Apply a voltage of 5 V between Vta 1 and E2 2 and check the change in voltage between 2 and Vc 3.
Page 354: Disassembly Of The Starter Motor
Electrical System 3) Disassembly of the Starter Motor Mark the starter motor body and the cap with a locating mark (for ease of reassembly). Slide the pinion stopper 1 downward as shown and remove the clip 2. Use a small flathead screwdriver to remove the clutch.
Page 355: Inspection Of The Brush
Measure the outer diameter of the commutator 1. Replace the starter motor assembly if the value is below the specified value. Commutator Outer Diameter: Standard Value 28.2 to 28.5 mm (1.110 to 1.122 in) Wear Limit: 28.0 mm (1.102 in) Measure the undercut a of the commutator 1.
Page 356: Starter Motor Operation Test
Electrical System 7) Starter Motor Operation Test Assemble the starter motor and, before and after installing it in the power unit, apply an electric current between the positive and negative points to confirm that it is working normally. Be careful of fire, because the operating test generates sparks.
Page 357: Ecu Coupler
• Measurement conditions Circuit tester to be used: HIOKI3030 • Permissible error of resistance is ±20% Note) 1 HIOKI HiTESTER MODEL 3030 was used for this measurement. Using another tester can result in an abnormal resistance value and an inaccurate test. 2 Disconnect all connections and measure as a separate unit.
Page 358 Electrical System Terminal Name Lead Wire (Color) CAN (H) White Diagnosis (-) Black Blank Diagnosis Yellow Diagnosis White Blank Blank Blank Blank CAN (L) Blue ECU Power Supply 123456789 Diagnosis Communication Red/White Power Supply (5 V) Blank 0qwertyui Blank Blank ECU B Connector Blank Blank...
Page 359 Troubleshooting 1. Troubleshooting List …………………… 9-2 Lubrication System ……………………… 9-12 Power Unit ………………………………… 9-3 Cooling System …………………………… 9-13 State 1 Engine will not start or is State 3 Engine rotation is unstable or hard to start. ……………………… 9-3 hunting occurs in low Starting System ……………………………...
Page 360: Troubleshooting List
Troubleshooting 1. Troubleshooting List * Low speed ESG is activated Probable Cause Fuel tank is empty Connection of the fuel system is incomplete Fuel system is taking in air or is clogged Fuel pipe is twisted or damaged Air vent screw of the fuel tank is not open Fuel filter, fuel pump, vapor separator, or injector is clogged Performance of the fuel pump or vapor separator has dropped Gasoline is of poor quality...
Page 361: Power Unit
Before working on the engine, check the installation condition of the hull, rigging and engine, and make sure the fuel is normal and the battery is fully charged. For mechanical troubleshooting, refer to the relevant troubleshooting section in this chapter. For checking and servicing the outboard motor, refer to the service procedures described in this manual to perform the work safely.
Page 362 Troubleshooting Check electrical conductivity of neutral switch. Conductive? Check start switch or main switch. Normal? Check electrical conductivity of wire harness. Conductive? 4st 25/30 2022...
Page 363: Ignition System
Ignition System Check spark plugs. Clean and adjust spark Normal? plugs, or replace. WARNING • When testing, cover the electrode cap properly so as to prevent Use spark tester to check leaks and contact with the wiring of the spark tester. ignition sparks.
Page 364 Troubleshooting Replace ignition coil. Normal? Check coil ass’y (exciter coil) resistance. Normal? Replace coil ass’y. Check ECU. 4st 25/30 2022...
Page 365: Fuel System
Fuel System Use the "Air purging for high pressure fuel circuit" Check operation of function in the diagnosis menu and check the fuel feed pump (FFP). operation of the fuel feed pump (FFP). Check electrical conductivity Operating noise of wire harness and fuse. heard? Conductive? Check output from ECU to...
Page 366 Troubleshooting Check mechanical fuel pump. Normal? Check vapor separator needle valve for bend or wear. Normal? 4st 25/30 2022...
Page 367: State 2 Full Throttle Engine Revolution
Full throttle engine revolution speed is low. Engine revolution speed falls off. Engine stalls. State 2 (Defective acceleration or deceleration) Check battery cables for defective contact, and ground lead wire securing bolt for looseness or disconnection. Normal? Check throttle position sensor and ISC valve connectors for connections.
Page 368: Ignition System
Troubleshooting Ignition System Check spark plugs. Normal? WARNING • When testing, cover the electrode cap properly so as to prevent Use spark tester to check leaks and contact with the wiring of the spark tester. ignition sparks. • Keep flammable gas, fuel, and oils away, because testing generates sparks.
Page 369: Fuel System
Fuel System Measure fuel pressure. Within specified Check fuel filter for clogging range? and dirt, and piping for leak. Repair and clean or Normal? replace defective parts. Check injector clogging Replace fuel regulator. and resistance. Replace injector. Normal? Check fuel pump. Replace fuel pump.
Page 370: Lubrication System
Troubleshooting Lubrication System Check engine oil level. Within specified range? Check oil pressure switch. Normal? Measure hydraulic pressure. Check oil pump for damage Normal? and oil leak. Clogging or leak? 9-12 4st 25/30 2022...
Page 371: Cooling System
Cooling System Check cooling water passage for clogging or leak. Normal? Check thermostat. Normal? Measure engine temperature sensor resistance. Normal? Check water pump. Normal? 4st 25/30 2022 9-13...
Page 372: State 3 Engine Rotation Is Unstable Or
Troubleshooting State 3 Engine rotation is unstable or hunting occurs in low speed range. Check throttle position sensor and ISC valve connectors for connections and resistances. Normal? Check throttle link and throttle valve for play and wear. Normal? Check intake manifold for air leak.
Page 373: Ignition System
Ignition System Check spark plugs. Normal? WARNING Use spark tester to check • When testing, cover the electrode cap properly so as to prevent ignition spark. leaks and contact with the wiring of the spark tester. • Keep flammable gas, fuel, and oils away, because testing generates sparks.
Page 374: Fuel System
Troubleshooting Fuel System Check fuel filter for clogging and dirt, and piping for leak. Normal? Check fuel pump. Normal? Check vapor separator needle valve for bend or wear. Normal? Check injector clogging and resistance. Normal? 9-16 4st 25/30 2022...
Page 375: Unit
PT Unit State 1 PT unit will not operate. Check operation of PT motor. Operating Check battery and fuse. noise heard? Normal? Check electrical conductivity of PT switch. Conductive? Check electrical conductivity of PT solenoid. Conductive? Check wire harness between battery, PT solenoid and PT switch.
Page 376: State 2 Pt Unit Is Not Capable Of
Troubleshooting Check PT fluid level. Within specified Add PT fluid to specified range? level. Disassemble PT unit to check. State 2 PT unit is not capable of sustaining the outboard motor. Check that manual valve is closed. Close manual valve. Closed? Check PT fluid level.
Page 377: Diagnosis
Diagnosis An electronically controlled engine can be connected to a PC to diagnose the status of the engine. Information that can be viewed include self-diagnosis, malfunction records, and status during operation. The operation of individual electronic components of the engine can be viewed to determine the malfunction.
Page 378 Troubleshooting 9-20 4st 25/30 2022...
Page 379 Rigging r/min r/ in 1. Service Information …………………… 10-2 2) Installation of the Remote Control Cable 2. Service Data ……………………………… 10-2 (Engine Side) 1) Boat Mounting Restriction ……………… 10-2 Remote Control Model ………………… 10-10 2) Mounting Dimensions …………………… 10-2 6. Lower Unit ………………………………… 10-15 3) Transom Dimensions ……………………...
Page 380: Service Information
Rigging r/ in 1. Service Information The installer shall ensure the work environment is safe by paying adequate attention to factors including fire prevention and ventilation so as not to cause injuries or damage the product. 2. Service Data 1) Boat Mounting Restriction Be careful not to overload the boat or mount an engine with an output that is too large for the boat.
Page 381: Transom Dimensions
3) Transom Dimensions Manual Tilt Model 231 mm (9.10 in) Gas-Assist/Power Tilt Model 351 mm (13.80 in) 327 mm (12.85 in) 251 mm (9.90 in) Permissible transom board thickness: 40 to 60 mm (1.55 to 2.35 in) 4st 25/30 2022 10-3...
Page 382: Lifting Up The Outboard Motor
Rigging r/ in a: The transom height is the height from the bottom of the boat hull to the top of transom board. 4) Lifting Up the Outboard Motor Use an engine hanger. 5) Installation of the Outboard Motor Install the outboard motor so that the interval c between the anti-ventilation plate a and the hull bottom b is 0 to 25 mm (0 to 1 in).
Page 383 Power Tilt/Gas-Assist Type Mark the mount holes and drill 4 holes with a diameter of 12.5 mm (0.49 in). Manual Tilt Type Decide the mounting location and firmly tighten the clamp screw handle. Mark the mount holes and drill 2 holes with a diameter of 9.0 mm (0.35 in).
Page 384: Fuel System
Rigging r/ in 3. Fuel System It is recommended to install an additional fuel/water separator on the boat to effectively remove water and foreign substances contained in the fuel. If a fuel/water separator of a wrong size is added to the fuel system, this may restrict the fuel and lead to the engine stalling or being damaged due to fuel starvation.
Page 385: Connections To The Outboard Motor
4. Connections to the Outboard Motor 1) Steering Cable Cable installed on the starboard side Apply a thin coat of grease over the entire cable end. Insert the steering cable into the tilt tube. Tighten the nut to the specified torque. Nut: 48 N·m (35 lb·ft) [4.8 kgf·m] •...
Page 386: Drag Link
Rigging r/ in 2) Drag Link Install the drag link as shown in the diagram. • Be sure to use a special bolt 1, nylon nuts 2 , washers 3, and a spacer 4 to install the drag link connecting the engine and the steering cable.
Page 387: Remote Control Components
5. Remote Control Components 1) Installation of the Remote Control Cable (Remote Controller Side) Loosen the screws 1 on the rear panel and remove the rear panel 2 . Screw about 11 mm (0.43 in) of the enclosed terminal eye 4 into the threaded section at the end of the remote control cable 3 and secure it with a nut 5 .
Page 388: Installation Of The Remote Control Cable (Engine Side) Remote Control Model
Rigging r/ in 2) Installation of the Remote Control Cable (Engine Side) Remote Control Model Release the latch attaching the bottom cowl and remove the top cowl. Remove the remote control stay cover 1 and the grommet (upper) 2. Remove the cable clip 3. Remove the cover 4.
Page 389 The shift cable is the one with the end that moves first when the control lever 5 is lowered (approx.32°) to the forward (F) side a until it stops. b Approx. 32° c Neutral position Pass the main harness 7 through the grommet (lower) 6 and attach the cable clip 3.
Page 390 Rigging r/ in With the control lever 5 on the remote control box at the neutral position, check that the free acceleration lever w is at the fully closed position. Operate the shift arm e to the forward (F), neutral (N), and reverse (R) positions to confirm the positions, then set it to the neutral (N) position.
Page 391 Tighten nuts t, then install the cable joint on the pins and secure them with the washers and snap pins y. Install the remote control stay cover 1. Operate the control lever and check that it moves to the forward (F), neutral (N), and reverse (R) positions. Check that the outboard motor shifts in when the control lever is lowered to the forward (F) side until it stops once (approx.
Page 392 Rigging r/ in Check that the throttle operates smoothly and repeat steps 9 to 16 as necessary. Reconnect the main harness connectors u. CAUTION Do not disconnect a main harness while the engine is in operation. Install the cover 4. 10-14 4st 25/30 2022...
Page 393: Lower Unit
6. Lower Unit 1) Installation of the Propeller WARNING • Before removing or installing the propeller, be sure to disconnect the battery cables from the battery and remove the stop switch lock plate. • When removing or installing the propeller, do not handle the propeller with your bare hands.
Page 394: Meters
Rigging r/ in 7. Meters 1) Installation of Meters When installing meters, select a place on the dashboard 1 where the operator can see them easily and they are not exposed to water spray. The meters can be installed on dashboards 1 that are 2 to 11 mm (0.08 to 0.43 in) thick.
Page 395: The Electrical System
8. The Electrical System 1) Battery Capacity 12 V 64 Ah/5 HR or higher 12 V 70 Ah/20 HR or higher 512 CCA or higher 2) Installation of the Battery Recommend connecting only the engine battery cables to the starting battery. Battery should be stored in battery storage box and secured to hull to prevent it from falling due to rolling or pitching or any shock in the place where it is protected...
Page 396: Wiring Diagram Of The Remote Controller And Meters
Rigging r/ in 3) Wiring Diagram of the Remote Controller and Meters A Side mount remote control head a Connection to the circuit for boat lights Lead Wire (Color) Part Name Black Remote Control Head Assembly (RC12F) Blue Tachometer Light Green Trim Meter Meter Lead Wire L = 2,000 (6.5 ft) White...
Page 397 B Top/flush mount remote control head a Connection to the circuit for boat lights Lead Wire (Color) Part Name Black Remote Control Head Assembly (Top/Flush) Green Tachometer Blue Trim Meter Light Green Main Switch Panel Buzzer White Meter Lead Wire L = 2,000 (6.5 ft) Yellow Extension Cable (Trim Sensor) L = 6,000 (19.5 ft) Yellow/Red...
Page 398: Installation Of The Trim Sensor
Rigging r/ in 9. Installation of the Trim Sensor Tilt the engine up fully and secure it with the tilt stopper. WARNING • Do not insert your hand or finger between t h e o u t b o a r d m o t o r a n d t h e c l a m p bracket while working.
Page 399 Install the clamp and the grommet. 4st 25/30 2022 10-21...
Page 400 Rigging r/ in Draw the trim sensor harness into the engine through the hole in the bottom cowl. Remove the remote control stay cover 1 and the grommet (upper) 2. Remove the cable clip 3. Pass the trim sensor wiring through the hole a of the grommet (lower) 4.
Page 401 Pass the shift cable 5 and the throttle cable 6 through the grommet (upper) 2 and place the unit onto the grommet (lower). Install the remote control stay cover 1. 4st 25/30 2022 10-23...
Page 402 Rigging r/ in 10-24 4st 25/30 2022...
Page 403 Wiring Diagram Wiring Chart …………………………………… 11-2 MFS25/30D EP/EPT MFS25/30D MF (Side Mount Remote Control Type/ Analog Meter) Electric Circuit …………… 11-8 (Basic Tiller Handle Type) Electric Circuit ……………………………… 11-5 MFS25/30D EP/EPT MFS25/30D EF/EFT (Top Mount Remote Control Type/ (Basic Tiller Handle Type) Analog Meter) Electric Circuit ……………...
Page 404 Wiring Diagram Wiring Chart Name Remarks Lead Wire Color Magneto Black Exciter Coil Blue Pulser Coil Black Pulser Coil Red/Yellow Black Ground White White ECU Charge Coil White Yellow Yellow Charge Coil Green Yellow Black Ground Yellow White Yellow Exhaust Cover Ground Ground Black...
Page 405 Name Remarks Lead Wire Color Red/White Service Connector Diagnosis Port White Yellow Black Resistance Red/White Red/White Fuse Option, 10A Black Black Battery Option Black/White Black Interface Unit Option USB conversion Option Option Meter Lamp Switch Option Blue Trim Sensor Option Pink Black Blue...
Page 406 Wiring Diagram 11-4 4st 25/30 2022...
Page 407 MFS25/30D MF (Basic Tiller Handle Type) Electric Circuit EXHAUST COVER (OPT) FUSE HOLDER MAGNETO CHARGE COIL (OPT) COIL (Service parts) EXCITER COIL BRACKET BATT (Service parts) PULSER COIL PULSER COIL COIL BRACKET ECU/CHARGE COIL FUEL INJECTOR Lg/R I/G COIL HEAD COVER FUEL INJECTOR Lg/B I/G COIL...
Page 408 MFS25/30D EF/EFT (Basic Tiller Handle Type) Electric Circuit EXHAUST COVER STARTER SOLENOID MAGNETO COIL FUSE HOLDER EXCITER COIL CHARGE COIL BRACKET BATT COIL BRACKET PULSER COIL PULSER COIL PT RELAY (UP) CYLINDER BLOCK(LEFT) (port side) NEUTRAL SWITCH PT RELAY (DOWN) ECU/CHARGE COIL CYLINDER BLOCK(LEFT)
Page 409 MFS25/30D EH/EHT (Multi-Function Tiller Handle Type) Electric Circuit EXHAUST COVER STARTER SOLENOID MAGNETO COIL FUSE HOLDER EXCITER COIL CHARGE COIL BRACKET BATT COIL BRACKET PULSER COIL PULSER COIL PT RELAY (UP) CYLINDER BLOCK(LEFT) (port side) NEUTRAL SWITCH PT RELAY (DOWN) ECU/CHARGE COIL CYLINDER BLOCK(LEFT)
Page 410 MFS25/30D EP/EPT (Side Mount Remote Control Type/Analog Meter) Electric Circuit EXHAUST COVER STARTER SOLENOID MAGNETO Volt meter COIL FUSE HOLDER (OPT) EXCITER COIL CHARGE COIL BRACKET FUEL LEVEL SENDER BATT (Commercially available product 33-240 ) COIL BRACKET PULSER COIL PULSER COIL PT RELAY (UP) Backlight CYLINDER BLOCK(LEFT)
Page 411 MFS25/30D EP/EPT (Top Mount Remote Control Type/Analog Meter) Electric Circuit EXHAUST COVER STARTER SOLENOID Volt meter (OPT) MAGNETO COIL FUSE HOLDER EXCITER COIL CHARGE COIL BRACKET FUEL LEVEL SENDER (Commercially available BATT product 33-240 ) COIL BRACKET Backlight PULSER COIL PULSER COIL PT RELAY (UP) Fuel meter...
Page 412 Copyright © 2022 Tohatsu Corporation. All rights reserved. No part of this manual may be reproduced or transmitted in any form or by any means without the express written permission of Tohatsu Corporation.
Page 413 S E R V I C E M A N U A L 4 STROKE MFS 25D MFS 30D Models 5-4, Azusawa 3-Chome, Itabashi-Ku Tokyo 174-0051, Japan Tel: +81-3-3966-3117 Fax: +81-3-3966-2951 OB No.003-21077-0BB2 2207NB www.tohatsu.com Printed in Japan...

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Mfs 35d 3vs-64110-0

TOHATSU MFS 25D Service Manual

1 Service Information

2 2 Service Data

3 3 Maintenance

4 Fuel System (Fuel Injection) 4

6 Lower Unit

7 Bracket

8 Electrical System

9 Troubleshooting

10 Rigging R/Min

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