TOHATSU M 70C User manual

M70C
Disassembling & Reassembling procedure
TOHATSU Corporation Japan
Service Div.

□M70C Open Packing ～PDI
<Open Packing of carton box ~ PDI>
Open the packing
Check the carton box breakage and damage surface of the packing before open the carton box.
Check the contents
Open the carton box and check the contents
Main part : Out board motor
Enclosed parts : Propeller, Fuel tank, Fuel hose, Tools, Owner’s manual, Transom bolts,
Spark plugs (2 pcs.), Emergency starter rope, and Tiller handle

PDI (abbreviation of Pre-Delivery Inspection)
Check and confirm about following items, using Pre-Delivery Inspection Check Sheet.
PDI sheet is as next page.
CHECK BEFORE OPERATION
CHECK DURING OPERATION
CUSTOMER DELIVERY CHECK LIST
[The procedure before PDI work]
It hangs to the stand an outboard motor using a hoist, then tighten transom bolts
(It is careful when carrying out hooking of the outboard motor.)
Install Tiller handle.
Check the external confirmation of scratches and cracks, according to a PDI sheet.

[Break- in]
Install test propeller (confirm to no free gap on the test propeller on the drive shaft.)
You must do break-in the engine by operating it for initial 10hours with mixing ratio by 25:1.
エラー!
When installing an outboard motor on a test tank, secure tighten bolts and fix to transom.
It tames and operation gives the familiarity nature of the inside parts of engine.
It is quite important procedure to extend the long term of the usage.
Please be sure to perform first time operation according to the owner's manual.
It makes a test run and each operation situation is checked.
Refer to the PDI sheet for each part check points.
It becomes the delivery to a customer after all operation checked.
*Necessity of the PDI
The outboard motors of Tohatsu are produced in a factory and confirm each adjustment by driving
before shipment.
Temperature or the humidity is different globally by a country and an area. The check before shipping
an outboard motor is necessary for these different places.
Naturally, the factory shipment is not done in a state to meet all countries and the area.
In addition, need to confirm if damage is not happen or not.
It is necessary to perform PDI before it is delivered an outboard motor to a customer by distributor
and/or dealers.

Trained personnel should check that the unit has been pre-delivered in accordance with the relevant To h a t s u
Outboard Manual. The following points must be confirmed at pre-delivery and during the water test.
RefNo:
MODEL PRIMARY ID (Port) PRIMARY ID (Starboard) HULL ID NUMBER (HIN)
BOAT MAKER/MODEL IGNITION KEY NUMBER (Port) IGNITION KEY NUMBER (Starboard) TRAILER NUMBER
CHECKBEFOREOPERATION CHECKDURINGOPERATION
All Standard Items Supplied (Defect, Breakage, Missing parts)
Engine Mounting (High, Width, Proper hardware, Secured)
Harness and hoses installation (Secured and Properly Dressed)
Main Wire Harness installation Extended ft No Extended
Multifunction Gage Dip Switch Setting for Application
Instrument Operation/Connections
Tiller Handle Installation/Secure
RemoteControlOperation/Adjustments Type:
CableStrokeandRouting Length: m Min.radius: cm
Shift Throttle Operation
CableStrokeandRouting Length: m Min.radius: cm
MechanicalSteeringOperation/Installation Maker:
HydraulicSteeringOperation/Bleed Maker:
Primer Pump Installed Properly (Arrow pointing up)
Fuel Line/Tank Installation/Connections Routing Sealed/Secured
InnerDiameter: m
Length: m Height: m
BoatFuelFilter Type
FuelVacuumTestResult: kPa@WOT rpm(over 50ps)
BatteryMeets/ExceedsEngineSpecifications Type:
Battery Charged/Secured/Connections Tight
Battery Cable Installation and Routing
BatteryCableType: CableLength:
Battery S/W installation (Secured, Properly Connections)
Manual Tilt Operation
Power Trim/Tilt Operation
Lower Unit Oil Level
Overheat Warning System (Ground sensor lead on applicable models)
Visual Inspection of Engine
<2-Stroke Fuel and Oil Setup>
Break-InPremixRatio(ExceptTLDImodels) 25 : 1
Oil in Remote and Marine Engine Tank
To h a t s u TCW3 EquivalentQualityOilBrand:
Breed Oil Injection Pump / No air oil Injection Lines
Electric Oil Pump Function
<4-Stroke Oil Setup>
Check Engine Oil Level (Ensure unit is not overfilled)
Engine Oil Classification: Brand:
<Carburetion: 2 and 4-Stroke models>
Manual/Electric Choke Operation
Electric Starter Operation (Start in gear protection functions)
Manual/Electric Choke Operation
Neutral Switch function
Stop Switch/Emergency Switch Operation
Steering Operation
Throttle Operation/Friction Adjustment Neutral/Cruising
Proper Shift Cable Adjustment/Operation (F-N-R)
Cooling System Water Flow
Fuel/Oil/Water/Exhaust leaks
Oil Warning system Check (Equipped models)
Indicator Lamp and Buzzer
Oil and Temperature Warning functions (Equipped models)
Engine reaches operating temperature
Power Trim/Tilt Operation
Instrument Operation
Trim Tab Adjustment (retorque after operation)
Propeller Selection: Brand: To h a t s u Other:
Material: SUS AL Plastic
Model: Dia: Pitch:
IdleRPM Single/P: rpm S: rpm
IngearidleRPM Single/P: rpm S: rpm
Factory-recommendedW.O.T.RPMRange: rpm
W.O.T.RPM Single/P: rpm S: rpm
No Cavitations/Ventilation
Remarks:
Inspector’s signature Date
Dealer name Phone number
Dealership address
CUSTOMER DELIVERY CHECKLIST
Operation of Equipment/Boat Accessories Explained
(Proper Trim and Tilt operation demonstrated)
Operation/Orientation Ride with Dealership Personnel
Warranty/Owner’s Manual and Keys Given to Customer by Dealer.
Customer Introduced to Service Manager/Writer
Return-to-Port Operations (Oil System, RPM Reduction)
Gauge Operation/Warning Symbols Explained
2-Stroke: Use of To h a t s u 2 stroke/TC-W3 or Equivalent Rated Oil
4-Stroke: Use of To h a t s u 4 stroke or Equivalent Rated Oil
4-Stroke: Show Customer Proper Checking Procedures and Proper Level of
Engine Oil
Engine Break-in Procedure Explained
Maintenance/Care Schedule Explained
Advised of First Scheduled Maintenance
Warranty Coverage Explained to Customer’s Satisfaction,
Including Customer Responsibilities
Customer questions answered by Dealership Personnel
Break-in Time Placed on Engine by Dealership Personnel
hours: Minutes:
Customer name Phone number
Customer address
Customer signature Date
Date of Issue : / /2007 ORIGINAL TO BE HELD BY DEALER/COPY TO CUSTOMER
TOHATSU OUTBOARD MOTOR
Pre-Delivery Inspection Check List 2 and 4-Stroke Models
The above materia
l
has been explained and/or provided to me by dealership
p
ersonne
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.
My questions were answered and explained to my satisfaction.

6
□M70C Maintenance section
Engine
<Disassembly>
Remove each terminal of harness from the power head.
CDI unit harness
Charge coil harness
Ignition coil harness
Lanyard stop switch harness
Each ground wire
Carburetor and throttle linkage connections
Shift linkage connection
Throttle and advance arm connection
Choke linkage connection

7
Fuel hose to fuel filter (In side)
Pilot hose connection
After removing each connection, remove an apron and engine attachment bolts.
Remove carburetors and inlet manifold.
Loose flywheel nut using special tool (Flywheel Puller kit 3C7-72211-1)
Remove flywheel from crankshaft using special tool (Flywheel Puller).
Remove oil re-circulation hose.
Remove, crank case mounting bolts and crankshaft from crankcase.
(Be careful not to damage the piston and piston ring)

8
Check the balance of crankshaft. Crank shaft Deflection Limit: 0.05mm
Inspection of power head cooling water passage
Remove thermostat cover and thermostat.
Remove cylinder head cover and exhaust cover.
Check corrosion and remove clogs and debris from cooling water passage.
Check thermostat, replace if the thermostat valve is open even a little at ambient temperature.

9
Engine
<Assembling>
Assembling engine reverse of their disassemble steps.
*Notes
(1) Install the crankshaft
When install crankshaft ass’y to cylinder, be careful not to apply excessive load to a piston and
a piston ring, and put in a piston in a sleeve.
Check the position of piston ring directions.
Check the dowel pin as allows for positioning upper main bearing.
The crankshaft of an attachment state
Check each position of main bearing and labyrinth packing between #1 and #2 cylinder, #2 and
#3 cylinder.
Size x Q'ty 1 st 2 nd
Cylinder head M8 x 14 1.2-1.5kg.m 3.0-3.5kg.m
Cylinder head cover M6 x 17 0.47-0.64kg.m
Exhaust cover M6 x 14 0.4-0.6kg.m 0.8-1.0kg.m
Intake manihold 0.4-0.6kg.m 0.8-1.0kg.m
Air silencer 0.27-0.36kg.m
8mm 1.2-1.5kg.m 2.4-2.6kg.m
10mm 1.7-2.3kg.m 3.8-4.2kg.m
Flywheel magneto 14.0-16.0kg.m
Carburetor bolt 0.47-0.64kg.m
Crankcase

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Check the position of lower main bearing located bottom of crankshaft.
Put certainly crankshaft thrust washer in the cylinder grooves.
(2) Apply sealing gasket to crank case
Degrease crank case and cylinder mating faces.
Apply sealing gasket (LOCTITE 518) to crankcase’s mating surface.

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(3) Check the connection of oil re-circulation hose.
(4) Check the position of each linkage such as original position.
Choke linkage connection
Throttle and advance arm connection
Shift linkage connection
Carburetor and throttle linkage connection
(5) Check the harness connection such as original position
Each grand wire
Lanyard stop switch harness
Ignition coil harness
Charge coil harness
CDI unit harness
(6) Check the fuel hose such as original position.
Fuel hose to fuel filter (inlet side)
(7) Check the pilot hose such as original position.

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Bracket
<Disassembly>
Tilt up the outboard motor.
Remove the shift lever shaft from bottom cowl.
Remove the spring pin of shaft rod joint using spring pin tool.
Remove the lower unit installation bolts, and pull lower unit ass’y.
Remove the engine gasket and lower motor cover.

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Remove the upper mount rubber instauration bolts.
Remove the lower mount rubber cap and lower mount rubber installation bolts.
Remove the ground wire bolt.
Tilt down drive shaft housing. Remove the ground wire as shown.
Remove the engine base and drive shaft housing.

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Bracket
<Assembling>
When assemble drive shaft housing parts, reverse the disassembling procedure.
Tightening torque as follows:
*Notes
Put in the dowel pin and assemble.
Connect ground wire.
Engine base seal rubber is certainly attached to the engine base.
Lower unit
＜Disassembly＞
Size x Q'ty 1 st
Engine mount bolt 1.9-2.1kg.m
Bracket nut 2.4-2.6kg.m
Mount rubber(upper) 4.0-5.0kg.m
Mount rubber(lower) 3.5-4.5kg.m
M8 2.4-2.6kg.m
M10 3.8-4.2kg.m
Gear case mount bolt

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Drain the gear oil.
Tilt up the outboard motor.
Remove the spring pin of shaft rod joint using spring pin tool (369-72217-0).
(Lower unit can be separated without removing of the gearshift shaft)
]
Remove the lower unit installation bolts, and separate the lower unit ass’y from the driveshaft
housing.
Remove the propeller shaft housing.

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When pulling out propeller shaft housing, remove clutch push rod steel ball together with the
housing ass’y as shown.
Remove the water pump housing, impeller and impeller key.
Fix gear case on a vise with propeller shaft housing opening upper makes for easy work.
Remove the bevel gear nut using special tools (Bevel gear nut wrench (353-72231-0) and
socket (345-72232-0)).
Cover the wrench with rag to avoid the damage to the lower case.
Parts are removed the bevel gear B, the bevel gear A drive shaft spring and the drive shaft
spring guide from lower case. Each part should be cleaned. Otherwise the backlash can not
have correct measurement if gear oil remains surface of gears.

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*About necessity of the backlash measurement management
The recent outboard motor tends it to be upsized.
The gear in the lower unit transmits the big output to a propeller only by the primary gear
reduction of bevel gear.
The load to depend on each gear becomes a considerably much bigger.
In addition, the gear case is used in the water. Therefore it is necessary that the volume of
lower case should be smaller as possible, to reduce the water resistance.
Therefore the capacity of the gear oil becomes that it was limited.
Use environment is severe, and as for the lower unit that lubricating oil capacity is limited which
is totally heavy condition to the lower unit.
It suffers from backlash management to maintain to use gear tooth contact in best condition for
long term.
Gear life shortens when negligence of the backlash management.
Please identify a method of the maintenance as necessity of the backlash management.
[The backlash]
There are three kinds of gears (A, B and C) in the case.
These have the processing dimensions gaps of a gear case and need an adjustment using
shims for three gears. This adjustment is needed to have a best gear tooth.
These are to become the backlash (same as for the tooth contact) same as a design standard.
It is done backlash adjustment in a factory, and it is shipped to the world. The way of thinking is
as follows.
【Measurement of Backlash】
B gear shim
A gear shim C gear shim

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1. Assemble the drive shaft spring, the guide drive shaft spring, the drive shaft, A gear, B gear,
and propeller shaft housing to the case.
In this case, attach the same shim.
Tighten each bolt and nut as specified torque. (Apply Three bond 1342 to the thread after
degreasing.)
*For this process, you do not need to assemble the water pump parts concerned.
2. Adjust the gap aas specified spec.
Pinion gear height: 0.60~0.64mm
3. Assemble the below special tool to the lower case and turn the driveshaft tightening the bolt
of a. When the driveshaft has lightly heavy, turn the nut additionally 180 degree.
This is to fix the A gear for backlash measurement.
a
Size 1 st
Bevel gear nut 4.0-6.0kg.m
M8 2.4-2.6kg.m
M10 3.8-4.2kg.m
Gear case mount bolt

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4. Turn the driveshaft 6 times by pulling the driveshaft to the top side. This means for stable
thrust taper roller bearing contact.
5. Attach backlash measuring tool clamp to the driveshaft.
6. Measure the backlash 4 points by each 90 degree.
Proper backlash A-B : 0.24-0.48mm
Proper backlash B-C : 0.24-0.48mm
Shim variation A gear 0.10/0.15
B gear 0.10/0.15/0.30
C gear 0.10/0.15
*When you measure the backlash, better to settle lower side as shown.
The reason is for stable thrust taper roller bearing contact.
In addition, when you measure the backlash, hold the driveshaft by your hand closely to the
lower case. The reason is the drive shaft shakes caused by hand and a correct measurement
is not possible.

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7. Reassembling procedure after your result is within the proper backlash.
8. If your result is out of specification, disassemble again and add or less a shim and assemble
and measure the backlash. When you measure the backlash, tighten the nut with
specification torque.
*For this process, you do not need to assemble the water pump parts concerned.
9. After you confirm the backlash, then check the tooth contact using gear tooth marker.
Apply the gear tooth maker surface of the tooth as shown.
Put the pre-load to the A gear about 10kg by hand.
Turn the driveshaft 6 times by pulling the driveshaft to the top side.
This is to mark the gear tooth contact on surface of the gear tooth.
Disassemble the A gear and check the gear tooth contact if the gear tooth contact is tendency
of toe or heel.