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Yanmar 2TNV70 Service Manual

Industrial diesel engine
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  • Page 2 Publication No. M9961-02E070 History of Revision Manual Name Service Manual for Industrial Diesel Engine Engine Model: 2TNV, 3TNV series (Indirect Injection System) Number Reason for Correction item Corrected Date of Outline of correction correction No (page) revision revision New edition September 2003 Printed in Japan M9961-02E070...

  • Page 3: Proposition 65 Warning

    PREFACE This manual describes the service procedures for the TNV series engines of indirect injection system that have been certified by the US EPA, California ARB and/or the 97/68/EC Directive for industrial use. Please use this manual for accurate, quick and safe servicing of the said engine. Since the explanation in this manual assumes the standard type engine, the specifications and components may partially be different from the engine installed on individual work equipment (power generator, pump, compressor, etc.).

  • Page 4: Safety Labels

    SAFETY LABELS Most accidents are caused by negligence of basic safety rules and precautions. For accident prevention, it is important to avoid such causes before development to accidents. Please read this manual carefully before starting repair or maintenance to fully understand safety precautions and appropriate inspection and maintenance procedures.

  • Page 5: Safety Precautions

    Safety Precautions (1) SERVICE AREA Sufficient Ventilation Inhalation of exhaust fumes and dust particles may be hazardous to ones health. Running engines welding, sanding, painting, and polishing tasks should be only done in well ventilated areas. Safe / Adequate Work Area The service area should be clean, spacious, level and free from holes in the floor, to prevent “slip”...
  • Page 6 (4) GENUINE PARTS and MATERIALS Genuine Parts Always use genuine YANMAR parts or YANMAR recommended parts and goods. Damage to the engine, shortened engine life and or personal injury may result.
  • Page 7 (5) FASTENER TORQUE Torqueing Fasteners Always follow the torque values and procedures as designated in the service manual. Incorrect values, procedures and or tools may cause damage to the engine and or personal injury. (6) Electrical Short Circuits Always disconnect the (-) Negative battery cable before working on the electrical system.

  • Page 8: Rotating Parts

    (8) FURTHER PRECAUTIONS Fueling / Refueling Keep sparks, open flames or any other form of ignition (match, cigarette, etc.) away when fueling/refueling the unit. Fire and or an explosion may result. Hot Surfaces. Do NOT touch the engine (or any of its components) during running or shortly after shutting it down.
  • Page 9 Precautions for Service Work (1) Precautions for Safety Read the safety precautions given at the beginning of this manual carefully and always mind safety in work. (2) Preparation for Service Work Preparation is necessary for accurate, efficient service work. Check the customer ledger file for the history of the engine.
  • Page 10 (2) How to Read the Explanations An exploded view, sectional views, a system diagram, etc. are shown at the beginning of each section as required for easy understanding of the mounted states of the components. For the removal/installation of each part, the procedure is shown with the procedural step No. in the illustration.
  • Page 11 Contents omitted in this manual Though the following jobs are omitted in the explanation in this manual, they should be conducted in actual work: Jacking up and lifting Cleaning and washing of removed parts as required Visual inspection (3) Definition of Terms [N OTICE]: Instruction whose negligence is very likely to cause an accident.

  • Page 12: Table Of Contents

    CONTENTS 1. General ....................... 1 1.1 Engine Nomenclature ......................1 1.2 Specifications........................... 1 1.3 Fuel Oil, Lubricating Oil and Cooling Water................7 1.3.1 Fuel oil............................7 1.3.2 Lubricating oil ...........................8 1.3.3 Cooling water ...........................8 1.4 Engine External Views......................9 1.5 Structural Description ......................10 1.6 Exhaust gas emission regulation....................11 1.6.1 The Emission Standard in USA ....................11 1.6.2 Engine identification .......................12...
  • Page 13 4. Disassembly, Inspection and Reassembly of Engines......48 4.1 Complete disassembly and reassembly ................48 4.1.1 Introduction ..........................48 4.1.2 Special service tools.......................49 4.1.3 Complete disassembly ......................54 4.1.4 Precautions before and during reassembly ................58 4.1.5 Adjusting operation.........................58 4.2 Cylinder Head: Disassembly, Inspection and Reassembly............ 59 4.2.1 Components (2-valve cylinder head)..................59 4.2.2 Disassembly procedure: ......................59 4.2.3 Reassembly procedure: ......................59...
  • Page 14 6. COOLING SYSTEM.................. 91 6.1 Cooling Water System ......................91 6.2 Cooling Water Pump Components ..................91 Disassembly (Reverse the below procedure for reassembly)..........92 6.4 Servicing Points........................92 7. FUEL INJECTION PUMP / GOVERNOR..........93 7.1 Introduction..........................93 7.2 Fuel Injection Pump....................... 93 7.2.1 Fuel system diagram ......................93 7.2.2 External view and components ....................94 7.2.3 Disassembly procedure:......................95...
  • Page 15 10. Electric Wiring ..................108 10.1 Electric Wiring Diagram ..................... 108 10.1.1 Alternator ..........................109 10.1.2 Starter..........................110 10.1.3 Current limiter........................111 10.1.4 Section area and resistance of electric wire ............... 112 11. SERVICE STANDARDS.................113 11.1 Engine Tuning........................113 11.2 Engine Body ........................114 11.2.1 Cylinder head ........................

  • Page 16: General

    2) Engine rating conditions are as follows (SAE J1349, ISO 3046/1) Atmospheric condition: Room temp. 25 , Atmospheric press. 100 kPa (750mm Hg), Relative humidity 30% Fuel temp: 40 (Fuel injection pump inlet) With cooling fan, air cleaner, exhaust silencer (Yanmar standard parts) After running-in hours. Output allowable deviation:...
  • Page 17 1. General (1) 2TNV70 Engine name Unit 2TNV70 Engine specification class Type Vertical, in-line, 4-cycle, water-cooled diesel engine Combustion chamber Indirect injection Number of cylinders Cylinder bore stroke 70 74 Displacement 0.570 Revolving Continuous speed rating Output (NET) (ps) Revolving...
  • Page 18 1. General (2) 3TNV70 Engine name Unit 3TNV70 Engine specification class Type Vertical, in-line, 4-cycle, water-cooled diesel engine Combustion chamber Indirect injection Number of cylinders Cylinder bore stroke 70 74 Displacement 0.854 Revolving 3000 3600 Continuous speed rating 12.1 14.5 Output (NET) (ps) (16.5)
  • Page 19 1. General 3TNV70 (continue) Engine name Unit 3TNV70 Engine specification class Type Vertical, in-line, 4-cycle, water-cooled diesel engine Combustion chamber Indirect injection Number of cylinders Cylinder bore stroke 70 74 Displacement 0.854 Revolving Continuous speed rating Output (NET) (ps) Revolving 3000 2000 2100...
  • Page 20 1. General (3) 3TNV76 Engine name Unit 3TNV76 Engine specification class Type Vertical, in-line, 4-cycle water-cooled diesel engine Combustion chamber Indirect injection Number of cylinders Cylinder bore stroke 76 82 Displacement 1.115 Revolving 3000 3600 Continuous speed rating 15.1 17.7 Output (NET) (ps) (20.5)
  • Page 21 1. General 3TNV76 (continue) Engine name Unit 3TNV76 Engine specification class Type Vertical, in-line, 4-cycle water-cooled diesel engine Combustion chamber Indirect injection Number of cylinders Cylinder bore stroke 76 82 Displacement 1.115 Revolving Continuous speed rating Output (NET) (ps) Revolving 2000 2100 2200...

  • Page 22: Fuel Oil, Lubricating Oil And Cooling Water

    1. General 1.3 Fuel Oil, Lubricating Oil and Cooling water 1.3.1 Fuel oil IMPORTANT: Only use the recommended fuel to obtain the best engine performance and prevent damage of parts, also prevent air pollution. (1) Selection of fuel oil Use the following diesel fuels for best engine performance: BS 2869 A1 or A2 Fuels equivalent to Japanese Industrial Standard, JIS.

  • Page 23: Lubricating Oil

    1. General 1.3.2 Lubricating oil IMPORTANT: Use of other than the specified lube oil may cause inner parts seizure or early wear, leading to shorten the engine service life. (1) Selection of lube oil Use the following lube oil API classification CD or CF (Standards of America Petroleum Institute) SAE viscosity...

  • Page 24: Engine External Views

    1. General 1.4 Engine External Views...

  • Page 26: Exhaust Gas Emission Regulation

    1. General 1.6 Exhaust gas emission regulation The engines in this manual have been certified by the US EPA and/or California. California Proposition 65 Warning Diesel engine exhaust and some of its constitutions are known to the State of California to cause cancer, birth defects, and other reproductive harm.

  • Page 27: Engine Identification

    1. General 1.6.2 Engine identification To identify the engines, the following emission control labels are affixed on the engines. (1) Emission control labels of US EPA EPA label for constant speed engines EPA label for variable speed engines (2) Emission control label for both EPA and ARB...

  • Page 28: Guarantee Conditions For The Epa Emission Standard

    1. General 1.6.3 Guarantee Conditions for the EPA Emission Standard The following guarantee conditions are set down in the operation manual. In addition to making sure that these conditions are met, check for any deterioration that may occur before the required periodic maintenance times.
  • Page 29 1. General (4) Perform maintenance without fail. Note: Inspections to be carried out by the user and by the maker are divided and set down in the “List of Periodic Inspections” and should be checked carefully. (5) Maintenance period and Quality guarantee period for exhaust emission related parts The maintenance of the parts related to the exhaust emission must be carried out in the maintenance period as shown in the below table.

  • Page 30: Inspection And Adjustment

    2. Inspection and Adjustment 2. Inspection and Adjustment 2.1 Periodic Maintenance Schedule The engine periodic inspection timing is hard to determine as it varies with the application, load status, qualities of the fuel and lube oils used and handling status. General rules are described here. :User-maintenance :Parts replacement :Shop-inspection...

  • Page 31: Periodic Inspection And Maintenance Procedure

    2. Inspection and Adjustment 2.2 Periodic Inspection and Maintenance Procedure 2.2.1 Check before Daily Operation Be sure to check the following points before starting an engine every day. Inspection Item Visual check around engine Fuel tank level check and fuel supply Lube oil level check and replenishment Cooling water level check and replenishment Fuel pipe and cooling water pipe inspection and maintenance...
  • Page 32 2. Inspection and Adjustment (Unit: liter) Model Class Total volume Effective volume 2TNV70 VM/VH 3TNV70 VM/VH 3TNV76 Lube oil capacity may differ from the above volume depending on an engine installed on a machine unit. (b) Replenishing oil pan with lube oil If the remaining lube oil level is low, fill the oil pan with the specified lube oil to the specified level through the filler port.

  • Page 33: Inspection After Initial 50 Hours Operation

    Standard Engine: The radiator shall be filled up. (Unit: liter) Model Cooing water volume in an engine 2TNV70 3TNV70 3TNV76 Engine cooling water capacity may differ from the above volume depending on an engine installed on a machine unit. (5) Fuel pipe and cooling water pipe inspection and maintenance Check the rubber hoses for fuel and cooling water pipes cracked.
  • Page 34 2. Inspection and Adjustment 2.2.2 inspection after initial 50 hours operation Be sure to check the following points after initial 50 hours operation, thereafter every 250 hours or 3 months operation. Inspection Item Lube oil and filter replacement V-belt tension check (1) Lube oil and filter replacement When an engine is still hot, be careful with a splash of lube oil which may cause burns.
  • Page 35 2. Inspection and Adjustment (c) Filling oil and inspection Fill with new lube oil until it reaches the specified level. IMPORTANT: Do not overfill the oil pan with lube oil. Be sure to keep the specified level between upper and lower limit on the dipstick. Warm up the engine by running for 5 minutes while checking any oil leakage Stop the engine after warming up and leave it...
  • Page 36 2. Inspection and Adjustment 2) If necessary, adjust the V-belt tension (deflection).a To adjust the V-belt tension, loosen the set bolt and move the alternator to tighten the V-belt. 3) After replacing with a new V-belt and adjusting it, run the engine for 5 minutes and readjust the deflection to the value in the table above.

  • Page 37: Inspection Every 50 Hours

    2. Inspection and Adjustment 2.2.3 Inspection every 50 hours Be sure to check the following points every 50 hours operation. Inspection Item Fuel tank draining Water separator draining Bleeding the fuel system Battery electrolyte level check and battery recharging (1) Fuel tank draining 1) Prepare a waste oil container.
  • Page 38 2. Inspection and Adjustment (3) Bleeding the fuel system Bleed the fuel system according to the following procedures. When there is air in the fuel system, the fuel injection pump will not be able to function. 1) Check the fuel oil level in the fuel tank. Refuel if insufficient.
  • Page 39 2. Inspection and Adjustment Battery structure (1) Electrolyte level Check the level of fluid in the battery. When the amount of fluid nears the lower limit, fill with battery fluid (available in the market) to the upper limit. If operation continues with insufficient battery fluid, the battery life is shortened, and the battery may overheat and explode.
  • Page 40 2. Inspection and Adjustment (b) Measurement with hydrometer When using a hydrometer, the measured specific gravity must be corrected according to the temperature at the time of measurement. The specific gravity of battery electrolyte is defined with 20 as the standard. Since the specific gravity increases or decreases by 0.0007 when the temperature varies by 1 , correct the value according to the equation...

  • Page 41: Inspection Every 250 Hours Or 3 Months

    2. Inspection and Adjustment 2.2.4 Inspection every 250 hours or 3 months Be sure to check the following points every 250 hours or 3 months operation, whichever comes first. Inspection Item Lube oil and filter replacement Radiator fin cleaning V-belt tension check Inspection and adjustment of governor lever and accelerator Air cleaner cleaning and element replacement (1) Lube oil and filter replacement (The second replacement and after)
  • Page 42 2. Inspection and Adjustment or stretch the wire to cause irregular engine speed control. Checking and adjusting procedure are as follows. 1) Check that the governor lever of the engine makes uniform contact with the high idling and low idling limiting bolt when the accelerating devices is in the high idling speed or low idling speed position.

  • Page 43: Inspection Every 500 Hours Or 6 Months

    2. Inspection and Adjustment 2.2.5 Inspection every 500 hours or 6 months Be sure to check the following points every 500 hours or 6 months operation, whichever comes first. Inspection Item Water separator cleaning Fuel filter element replacement Air cleaner cleaning and element replacement (1) Air cleaner element replacement The cup of an water separator is translucent, and the inside can be seen.
  • Page 44 2. Inspection and Adjustment 4) Bleed the fuel system. Refer to 2.2.3.(3) IMPORTANT: Be sure to use genuine Yanmar part. Otherwise, it results in engine damage, uneven engine performance and decline of engine life. And, these troubles are outside the guarantee.

  • Page 45: Inspection Every 1,000 Hours Or One Year

    2. Inspection and Adjustment 2.2.6 Inspection every 1,000 hours or one year Be sure to check the following points every 1,000 hours or one year operation, whichever comes first. Inspection Item Cooling water replacement Diaphragm assy inspection Intake/exhaust valve clearance adjustment Fuel injection nozzle pressure inspection ( 1) Cooling water replacement Cooling water contaminated with rust or water scale reduces the cooling effect.
  • Page 46 2. Inspection and Adjustment g) When filling with the cooling water for the first time or replacing, the air contains in the cooling water system. So as the air in the cooling water system is made self-bleeding during engine operation, the cooling water level in the radiator and coolant recovery tank will be lowered.
  • Page 47 2. Inspection and Adjustment 3) Valve clearance measurement Insert a thickness gage between the rocker arm and valve cap and record the measured valve clearance. (Use it as data for estimating the wear state.) 4) Adjusting other cylinders Then in case of 3-cylinder engines turn the crankshaft clockwise viewed from radiator side at 240 degree, and adjust the valve clearance for the No.3 cylinder.
  • Page 48 2. Inspection and Adjustment (4) Fuel injection nozzle pressure inspection Wear protective glasses when testing injection from the fuel injection valve. Never approach the injection nozzle portion with a hand. The oil jetting out from the nozzle is at a high pressure to cause loss of sight or injury if coming into careless contact with it.
  • Page 49 2. Inspection and Adjustment [Informative: Fuel injection valve structure] (b) Spray pattern inspection After adjustment to the specified valve opening pressure, use a nozzle tester and check the spray attern and seat oil-tightness. Seat oil tightness check After injecting a few times, increase the pressure gradually. Hold the pressure for about 5 seconds at a little before the valve opening pressure of 1.96 Mpa(20kgf/cm ), and check to see that oil does not drip from the tip end of the nozzle.
  • Page 50 2. Inspection and Adjustment Spray and injection states Operate the nozzle tester lever at a rate of once or twice a second and check no abnormal injection. If normal injection as shown below cannot be obtained, replace the fuel injection valve. No extreme difference in angle(θ) Finely atomized spray Excellent spray departure...

  • Page 51: Inspection Every 2000 Hours Or 2 Years

    2. Inspection and Adjustment 2.2.7 Inspection every 2000 hours or 2 years Be sure to check the following points every 2,000 hours or two years operation, whichever comes first. Inspection Item Cooling water path flushing and maintenance Fuel pipe and cooling water pipe inspection and maintenance Intake/exhaust valve seat lapping Fuel injection timing adjustment Fuel injection pump inspection and adjustment...
  • Page 52 2200 Engine speed 2100 2600 3000 3600 3400 3600 2TNV70 Injection timing 3TNV70 (FID)bTDC Deg. 1 deg. 3TNV76 8) Repeat steps 5) to 7) a few times. Note: Injection timing check for one cylinder is generally sufficient. If it is to be checked for all cylinders of 3-cylinder engine, check each cylinder in the ignition order of: 1-3-2-1 by turning at each 240 degrees.

  • Page 53: Adjusting The No-Load Maximum Or Minimum Speed

    2. Inspection and Adjustment 2.3 Adjusting the no-load maximum or minimum speed 1) After warming the engine up, gradually raise the speed and set it at the no-load maximum speed. 2) If the no-load maximum revolution is out of the standard, adjust it by turning the high idle limiting bolt.

  • Page 54: Sensor Inspection

    2. Inspection and Adjustment 2.4 Sensor Inspection 2.4.1 Oil pressure switch Disconnect the connector from the oil pressure switch. Keep the voltammeter probes in contact with the switch terminal and cylinder block while operating the engine. It is abnormal if circuit is closed. 2.4.2 Thermo switch Place the thermo switch in a container filled with antifreeze or oil.

  • Page 55: Thermostat Inspection

    2. Inspection and Adjustment 2.7 Thermostat inspection Place the thermostat in a container filled with water. Heat it while measuring the water temperature, and see that the thermostat is actuated at temperature of following table. Valve opening Full open lift Temperature (Temperature) (deg C)*...

  • Page 56: Long Storage

    2. Inspection and Adjustment 2.9 Long storage Observe the following instructions when the engine is to be stored for a long period without operation: 1) Be sure to use clean soft water added Long Life Coolant Antifreeze (LLC) in the cooling water system and do not drain the coolant before long-term storage.

  • Page 57: Troubleshooting

    3. Troubleshooting 3. TROUBLESHOOTING 3.1 Preparation before troubleshooting If the signs of a trouble appear, it is important to lecture on the countermeasure and treatment before becoming a big accident not to shorten the engine life. When the signs of a trouble appear in the engine or a trouble occurs, grasp the trouble conditions fully by the next point and find out the cause of sincerity according to the troubleshooting.

  • Page 58: Quick Reference Table For Troubleshooting

    3. Troubleshooting 3.2 Quick Reference Table for Troubleshooting The following table summarizes the general trouble symptoms and their causes. If any trouble symptom occurs, take corrective action before it becomes a serious problem so as not to shorten the engine service life. Poor Insufficient Cooling...
  • Page 59 3. Troubleshooting Poor Insufficient Cooling Starting failure exhaust Hunting Lube oil Trouble symptom engine output water intake color Engine starts Exhaust During but stops color work soon. Exhaust Corrective action smoke Cause Excessive cooling effect of radiator Defective thermostat (kept closed) (See 2.7 in Chapter2.) Defective thermostat (kept opened)(See 2.7 in Chapter2.) Insufficient cooling effect of radiator or slipping fan belt (See 2.2.2-(2) in Chapter2.)
  • Page 60 3. Troubleshooting Poor Insufficient Cooling Starting failure exhaust Hunting Lube oil Trouble symptom engine output water intake color Engine starts Exhaust During but stops color work soon. Exhaust Corrective action smoke Cause Clogged air filter Clean. (See 2.2.4(5) and 2.2.5(3) in Chapter2.) Engine used at high temperatures or at high altitude Study output drop and load matching.

  • Page 61: Troubleshooting By Measuring Compression Pressure

    3. Troubleshooting 3.3 Troubleshooting by measuring Compression Pressure Compression pressure drop is one of major causes of increasing blowby gas (lube oil contamination or increased lube oil consumption as a resultant phenomenon) or starting failure. The compression pressure is affected by the following factors: 1) Degree of clearance between piston and cylinder 2) Degree of clearance at intake/exhaust valve seat 3) Gas leak from nozzle gasket or cylinder head gasket...
  • Page 62 3. Troubleshooting (3) Engine speed and compression pressure (for reference) (4) Measured value and troubleshooting When the measured compression pressure is below the limit value, inspect each part by referring to the table below. Item Cause Corrective action Air cleaner element Clogged element Clean the element.

  • Page 63: Disassembly, Inspection And Reassembly Of Engines

    4. Disassembly, Inspection and Reassembly of Engines 4. Disassembly, Inspection and Reassembly of Engines 4.1 Complete disassembly and reassembly 4.1.1 Introduction Make preparation as follows before starting engine inspection and service: 1) Fix the engine on a horizontal base. Be sure to fix the engine securely to prevent injury or damage to parts due to falling during the work. 2) Remove the cooling water hose, fuel oil pipe, wire harness, control wires etc.

  • Page 64: Special Service Tools

    − − Tolerance: − − ※Locally manufactured Valve spring compressor (for removal / yanmar code No. installation of valve 129100-92630 spring) Stem seal inserter (for inserting stem seal) ｄ3 15.0 11.0 4 or more Tolerance: d1±0.2 L1±0.1...
  • Page 65 Parts No. Cylinder bore cylinder liner) 129400-92410 70-76 Piston insertion tool (for inserting piston) Yanmar code No. 955500-02476 ※The above piston insertion tool is applicable to 60 –125 mm diameter pistons. Piston ring replacer (for removal / installation of piston ring)
  • Page 66 4. Disassembly, Inspection and Reassembly of Engines (2) Measuring instruments Instrument name Application Illustration Measurements of shaft bending, and strain and gap of surfaces Dial gage Measurements of narrow or deep portions that cannot be measured by dial gage Test indicator For holding the dial gage when measuring using a dial gage, standing angles adjustable...
  • Page 67 4. Disassembly, Inspection and Reassembly of Engines Instrument name Application Illustration For measuring valve spring inclination and straightness of parts Square For measuring shaft bend V-block For tightening nuts and bolts to the specified torque Torque wrench For measuring gaps between ring and ring groove, and shaft joints during assembly Thickness gage...
  • Page 68 For measuring the revolution regardless of the center or periphery of the revolving object. Fuel high-pressure pipe clamp type For measuring resistance, voltage and continuity of electrical circuits Circuit tester For measuring compression pressure Yanmar code No. TOL-97190080 Compression gage kit...

  • Page 69: Complete Disassembly

    4. Disassembly, Inspection and Reassembly of Engines 4.1.3 Complete disassembly Peripheral parts such as air cleaner, muffler and radiator differ in installation and types for each application. Therefore, description in this Chapter is started with the steps to be taken just after the peripheral parts have been removed.
  • Page 70 4. Disassembly, Inspection and Reassembly of Engines Step Removal Parts Remarks 1) Remove cylinder head tightening bolts. 1) Lay a cardboard or the like on the floor and 2) Remove a cylinder head assembly. place a cylinder head assembly on it so as 3) Remove a cylinder head gasket.
  • Page 71 4. Disassembly, Inspection and Reassembly of Engines Step Removal Parts Remarks 1) Remove flywheel mounting bolts. 1) Carefully protect the ring gear from damage. 2) Remove a flywheel. 1) Remove a flywheel housing. 1) Carefully protect the oil seal from damage. 2) Remove a oil seal.
  • Page 72 4. Disassembly, Inspection and Reassembly of Engines Step Removal Parts Remarks Alternatively, insert a thickness gauge directly between the base thrust metal and the thrust surface of the crankshaft to measure the gap. (Refer to 4.4.4 in Chapter 4.) If the measured gap exceeds the limit, replace the thrust metal with a new one.

  • Page 73: Precautions Before And During Reassembly

    4. Disassembly, Inspection and Reassembly of Engines 4.1.4 Precautions before and during reassembly To reassemble engine components, reverse the procedure of disassembly. However, follow the precautions below and the precautions from chapter 4 to chapter 7 particularly before and during reassembly.

  • Page 74: Cylinder Head: Disassembly, Inspection And Reassembly

    4. Disassembly, Inspection and Reassembly of Engines 4.2 Cylinder Head: Disassembly, Inspection and Reassembly 4.2.1 Components (2-valve cylinder head) 4.2.2 Disassembly procedure: Disassemble in the order of the numbers shown in the illustration. 1) Remove the alternator assy. (Point1 of 4.2.4) 2) Remove the fan, pulley and V belt.

  • Page 75: Servicing Points

    4. Disassembly, Inspection and Reassembly of Engines 4.2.4 Servicing points Point 1 [Disassemble] Loosen the mounting bolt while supporting the alternator. Do not tilt the alternator toward the cylinder block in haste since it may damage the alternator or pinch a finger.
  • Page 76 4. Disassembly, Inspection and Reassembly of Engines Point 6 Breather system (A reductor to intake air system of blowby gas) Emitting blowby gas is harmful to natural environment. Therefore blowby gas reductor is adopted to TNV series engines as breather system. The system of model 3TNV76 is shown as a representative of that breather system in the right figure.
  • Page 77 4. Disassembly, Inspection and Reassembly of Engines Point 7 [Disassemble] Keep the removed push rods by attaching tags showing corresponding cylinder Nos. [Reassemble] Always apply oil to the contact portions of the push rods and clearance adjusting screws. Point 8 [Disassemble] Loosen the cylinder head bolts in two steps in the illustrated order.

  • Page 78: Parts Inspection And Measurement

    4. Disassembly, Inspection and Reassembly of Engines 4.2.5 Parts Inspection and measurement (1) Cylinder head Clean the cylinder head, mainly the combustion surface, valve seats and intake/exhaust ports, remove carbon deposit and bonding agent, and check the surface state. (a) Appearance check Check mainly discoloration and crack.
  • Page 79 4. Disassembly, Inspection and Reassembly of Engines (2) Valve guide Mainly check damage and wear on the inside wall. Apply supply part code when replacing the part. Service part code 119717-11800 Valve stem clearance Part name Place Standard Limit Guide I.D. 6.000 6.012 6.08 Intake valve...
  • Page 80 4. Disassembly, Inspection and Reassembly of Engines (1) Valve spring Mainly inspect damage and corrosion. Free length standard Inclination limit 37.8 (2) Valve rocker arm Mainly inspect valve head cap contact surface, inside surface defects and wear. Slight surface defects shall be corrected with an oilstone.

  • Page 81: Valve Seat Correction

    4. Disassembly, Inspection and Reassembly of Engines (7) Push rod Mainly inspect the surface in contact with the tappet and adjusting screw. Slight defects shall be orrected with an oilstone. Bend limit 0.03mm or less (8) Valve clearance adjusting screw Mainly inspect the surface in contact with the push rod.

  • Page 82: Valve Guide Replacement

    4. Disassembly, Inspection and Reassembly of Engines 4.2.7 Valve guide replacement 1) Use a valve guide extraction tool(4.1.2(1) No.1 in Chapter 4) and extract the valve guide from the cylinder head. 2) Put liquid nitrogen or ether (or alcohol) with dry ice added in a container and put the valve guide for replacement in it for cooling.

  • Page 83: Gear Train And Camshaft

    4. Disassembly, Inspection and Reassembly of Engines 4.3 Gear Train and Camshaft 4.3.1 Components 4.3.2 Disassembly procedure: Disassemble in the order of the numbers in the illustration. 1) Perform steps 1) to 12) of the cylinder head disassembly procedure. 2) Remove the cooling water pump. 3) Remove the crankshaft pulley.

  • Page 84: Servicing Points

    4. Disassembly, Inspection and Reassembly of Engines 4.3.4 Servicing points Point1 [Disassemble] Remove the crankshaft pulley using a gear puller after removing the crankshaft pulley set bolt. When removing the pulley using the gear puller, use a pad and carefully operate so as not to damage the thread.
  • Page 85 4. Disassembly, Inspection and Reassembly of Engines Point4 [Reassemble] Assemble crankshaft gear A, fuel injection pump drive gear B and camshaft gear C at the same time by aligning with idle gear A, B and C marks. Install the idle gear shaft with the oil hole facing upward.

  • Page 86: Parts Inspection And Measurement

    4. Disassembly, Inspection and Reassembly of Engines 4.3.5 Parts inspection and measurement (1) Camshaft Mainly check the contact between the tappet and cam contact surface, bearing seizure and wear, and gear damage. (a) Shaft bend measurement Support the camshaft with V blocks. Rotate the camshaft and measure the distortion at the center of the camshaft and at each journal with a dial gage.

  • Page 87: Oil Seal Replacement

    4. Disassembly, Inspection and Reassembly of Engines (2) Idle gear Mainly check the metal seizure and wear, and gear damage. Shaft outside diameter and metal inside diameter measurement Item Standard Limit Shaft outside diameter 44.950 44.975 44.900 Metal inside diameter 45.000 45.025 45.075 Clearance...

  • Page 88: Cylinder Block

    4. Disassembly, Inspection and Reassembly of Engines 4.4 Cylinder Block 4.4.1 Components...

  • Page 89: Disassembly Procedure

    4. Disassembly, Inspection and Reassembly of Engines 4.4.2 Disassembly procedure: Disassemble in the order of the numbers in the illustration. 1) Perform steps 1) to 15) in the cylinder head disassembly procedure. 2) Perform steps 1) to 12) in the gear train disassembly procedure. 3) Remove the oil pan and the spacer.

  • Page 90: Servicing Points

    4. Disassembly, Inspection and Reassembly of Engines 4.4.4 Servicing points Point1: Oil pan [Disassemble] Sealant is applied to the oil pan mounting surface on the block. Carefully operate so as not to damage or distort the bonding surface. [Reassemble] Apply sealant (code No.977770-01212) before reassembly.
  • Page 91 4. Disassembly, Inspection and Reassembly of Engines Point 4: Journal bearing cap [Disassemble] Before removing the journal bearing, measure the crankshaft side gap. Measure it in either method because there are the next two methods. 1) Install a dial gage on the cylinder block, and move a crankshaft in front and back, and measure the side gap as shown in the right figure.
  • Page 92 4. Disassembly, Inspection and Reassembly of Engines Point 6: Piston pin and rings [Disassemble] Using the piston ring replacer (see 4.1.2(1) No.10 in Chapter 4), remove the piston rings. Remove the circlip and remove the piston pin by pushing it out. [Reassemble] Install each piston ring on the piston, with the punched manufacturer’s mark facing upward.

  • Page 93: Parts Inspection And Measurement

    4. Disassembly, Inspection and Reassembly of Engines 4.4.5 Parts inspection and measurement (1) Cylinder block Especially clean head surface, cylinder bores and oil holes, and check the below items after removing any carbon deposit and bonding agent. (a) Appearance inspection Check if there is any discoloration or crack.
  • Page 94 4. Disassembly, Inspection and Reassembly of Engines (c) If the limit is exceeded or any surface defect is found, repair by boring and honing. Use an oversized piston (and new piston rings) as required. Oversized piston (0.25 mm) Model Code No. Standard 2/3TNV70 70.250...
  • Page 95 4. Disassembly, Inspection and Reassembly of Engines (c) Crankpin and journal measurement Measure the outside diameter, roundness and taper at each crankpin and journal. Correct by grinding if unevenly wear, roundness exceeding the limit or insufficient outside diameter is found. Replace if the defect is excessive. Crankpin If a clearance is necessary, measure the inside diameter by following (5) d) "...
  • Page 96 4. Disassembly, Inspection and Reassembly of Engines Dimension R and finishing precision of crankshaft journal and pin As for grinding processing of journal and pin, machine it by using the grinding wheel of the dimension R of below table. Finishing precision standard of dimension R Surface finishing precision standard on journal and pin: Ry=0.8S super polishing...
  • Page 97 4. Disassembly, Inspection and Reassembly of Engines (4) Piston Especially clean the combustion surface, circumference, ring grooves and piston pin bosses, and check after removing any carbon deposit. Any burr at a ring groove or snap ring groove shall be removed.
  • Page 98 4. Disassembly, Inspection and Reassembly of Engines (b) Piston pin and piston pin hole measurement Measure the outside diameter of piston pin and the inside diameter of piston pin hole. Calculate the clearance between piston pin and piston pin hole. If any data exceeds the limit, replace the part with a new one.
  • Page 99 4. Disassembly, Inspection and Reassembly of Engines Piston ring dimension Model Part Item Standard Limit Ring groove width 1.550 1.570 Ring width 1.470 1.490 1.450 Top ring Side clearance 0.060 0.100 End clearance 0.15 0.30 0.39 Ring groove width 1.540 1.560 1.660 Ring width 1.470 1.490...
  • Page 100 4. Disassembly, Inspection and Reassembly of Engines (5) Connecting rod (a) Appearance inspection Inspect the portion near the boundary of the chamfered portion and I-beam section of the big and small ends of the connecting rod as well as the portion near the oil hole of the bushing at the small end for cracks, deformation, and discoloration.
  • Page 101 4. Disassembly, Inspection and Reassembly of Engines (d) Rod big end measurement Measure the crankpin outside diameter. The oil clearance is calculated as the difference in the crankpin outside diameter and the crank pin metal inside diameter (refer to 4.4.5.(2)(c) ). Replace the crankpin metal if a clearance becomes close to the limit value in the table below.

  • Page 102: Cylinder Bore Correction

    4. Disassembly, Inspection and Reassembly of Engines 4.4.6 Cylinder bore correction (a) Slight uneven worn, flawed, etc. shall be corrected by honing only. If the cylinder is unevenly worn partially, flawed or otherwise damaged and cannot be repaired simply by honing, rebore the cylinder first and then hone.

  • Page 103: Lubrication System

    5. Lubrication System 5. LUBRICATION SYSTEM 5.1 Lubrication System Diagram 5.2 Trochoid Pump Components Trochoid pump...

  • Page 104: Disassembly(Reverse The Below Procedure For Reassembly)

    5. Lubrication System 5.3 Disassembly(Reverse the below procedure for reassembly) 1) Loosen the belt, and remove the radiator pulley, fan and V-belt. (See 4.2.2. 2) in Chapter 4.) 2) Remove the crankshaft pulley. (See 4.3.2. 3) in Chapter 4.) 3) Remove the gear case cover. (See 4.3.2. 4) in Chapter 4.) 4) Remove the lube oil pump cover from the gear case cover.

  • Page 105: Parts Inspection And Measurement

    5. Lubrication System 5.5 Parts Inspection and Measurement 5.5.1 Trochoid pump inspection and measurement (1) Outside diameter clearance and side clearance of outer rotor Insert a gap gauge between the outer rotor and the gear case cover, and measure outside diameter gap. Put a ruler on the end face of the gear case cover, and insert a gap gauge between rotor, and measure a side gap.

  • Page 106: Cooling System

    6. Cooling System 6. COOLING SYSTEM 6.1 Cooling water System 6.2 Cooling Water Pump Components...

  • Page 107: Disassembly (Reverse The Below Procedure For Reassembly)

    6. Cooling System 6.3 Disassembly (Reverse the below procedure for reassembly) 1) Remove the alternator. (See 4.2.2. 1) in Chapter 4.) 2) Remove the fan, V-belt and pulley. (See 4.2.2. 2) in Chapter 4.) 3) Remove the thermostat case. (See 4.2.2. 3) in Chapter 4.) 4) Remove the cooling water pump.

  • Page 108: Fuel Injection Pump / Governor

    The careful consideration to avoid dust and rust at the time of disassembly, adjustment, reassembly of the fuel injection pump in the market is necessary. Fuel injection pumps manufactured by Yanmar, YPES-ML type series are inline type. A cam shaft is driven through the timing gear, and mechanical type fuel feed pump driven by a cam shaft sends fuel to the fuel filter from the fuel tank.

  • Page 109: External View And Components

    7. Fuel Injection Pump / Governor 7.2.2 External view and components...

  • Page 110: Disassembly Procedure

    7. Fuel Injection Pump / Governor 7.2.3 Disassembly procedure: The procedure to remove a fuel injection pump from the gear case is shown. [NOTICE] Be sure to remove a flange and a fuel injection pump drive gear with a pair without loosening the flange installation bolts.

  • Page 111: Confirmation And Adjustment Of The Fuel Injection Timing

    7. Fuel Injection Pump / Governor 7.2.5 Confirmation and adjustment of fuel injection timing Refer to 2.2.7 in Chapter 2. 7.2.6 Confirmation and adjustment of no-load maximum and minimum speed Refer to 2.3 in Chapter 2. And, fuel injection pipes, fuel pipes and a remote control wire are installed in the former condition.

  • Page 112: The Specifications Of A Starting Motor And The Characteristics

    A starting motor turns the ring gear installed on a engine flywheel by the pinion while overcoming resistance such as the compression pressure and the friction loss of the engine and makes the engine start. 8.1.1 Specifications Manufacturer’s model (Denso) P1.1 Yanmar code 119717-77010 Nominal output Weight Revolution direction (as viewed from pinion) Clockwise...

  • Page 113: The Structure Of A Starting Motor And The Wiring Diagram

    8. The specifications of a starting motor and the characteristics 8.2 The structure of a starting motor and the wiring diagram 8.2.1 Structure (1) Disassembly drawing (2) Structure When the starting switch is turned on, a magnet switch takes a voltage, and a pinion projects. The pinion engages with the ring gear of a engine, and the engine is started.

  • Page 114: Wiring Diagram Of A Starting Motor

    8. The specifications of a starting motor and the characteristics 8.2.2 Wiring diagram of a starting motor 1) When a starting switch is turned on, a magnet switch is charged, and a moving core is absorbed, and a pinion clutch is moved forward through a lever, and the pinion engages with a ring gear.

  • Page 115: Alternator

    9. Alternator 9. ALTERNATOR As a representative example of alternator, the alternators of 20A and 40A are shown in this chapter. 9.1 20A Alternator 9.1.1 Specifications Manufacturer’s model (Kokusan) GP9191 Yanmar code 119910-77200 Rating Continuous Battery voltage Nominal output Rated revolution...

  • Page 116: Structure

    9. Alternator 9.1.2 Structure...

  • Page 117: Wiring Diagram

    9. Alternator 9.1.3 Wiring diagram [NOTICE] 1) Don't do mis-connecting and short-circuit of each terminal. 2) Don't remove a battery terminal and a B terminal when rotating. 3) Shut out a battery switch during the alternator stop. 9.1.4 Standard output characteristics The standard output characteristics of this alternator are shown as the below figure.

  • Page 118: Inspection

    9. Alternator 9.1.5 Inspection (1) V belt inspection 4) Inspect the matter whether there are not crack, stickiness and wear on the belt visually. Check that a belt doesn't touch the bottom part of the pulley groove. If necessary, replace the V belt set.

  • Page 119: Alternator

    9. Alternator 9.2 40A Alternator 9.2.1 Components (1) Parts related to the alternator (2) Alternator components of disassembly and assembly...

  • Page 120: Specifications

    9. Alternator 9.2.2 Specifications Manufacturer’s model (Denso) ACFA68 Yanmar code 129423-77200 Rating Continuous Battery voltage Nominal output (13.5V heat) Rated revolution 5,000 Operating revolution 1,350 18,000 Grounding characteristics Minus side grounding Direction of revolution (viewed from pulley) Clockwise Integrated regulator...

  • Page 121: Standard Output Characteristics

    9. Alternator 9.2.4 Standard output characteristics The standard output characteristics of this alternator are shown as the right figure. 9.2.5 Inspection Perform the same procedure as that of 9.1.5 in Chapter 9.

  • Page 123: Electric Wiring

    10. Electric Wiring 10. Electric Wiring 10.1 Electric Wiring Diagram This is a typical example.

  • Page 124: Alternator

    (3) When the L line is used for control purposes Consult with Yanmar first before connecting any load other than the charge lamp to the L line. Damage to the alternator and related equipment will not be warranted without such prior consultation.

  • Page 125: Starter

    Be sure to use the safety relay to prevent over-running. This safety relay is supplied as an option. Consult Yanmar first when planning to install a safety relay at your own company. In the case of failure to consult with Yanmar, our warranty will not be applied to all the electrical equipment.

  • Page 126: Current Limiter

    (5) Non-use of the Yanmar wiring diagram Use without prior consultation of any wiring diagram other than that provided by Yanmar removes any breakdown of any electrical equipment from the warranty. (6) Installation environment Observe the following when installing the current limiter: 1) Do not install it on the engine.

  • Page 127: Section Area And Resistance Of Electric Wire

    10. Electric Wiring 10.1.4 Section area and resistance of electric wire (1) Allowable maximum cable length （Terminal resistance is not included.） Cable construction Note1 Ref. Note2 Cable size Resistance ( /m) Element No. Cable dia. 0.32 0.005590 0.36 3.58 8.94 0.32 0.003520 0.57...

  • Page 128: Service Standards

    2. Compression pressure 2/3TNV70 3.24(33) 0.1(1) 2.55(26) 0.1(1) (at 250 min ) 3TNV76 3.43(35) 0.1(1) 2.75(28) 0.1(1) MPa(kgf/cm Cooling water Capacity 2TNV70 (Only engine body) 2.2.1.(4) (Liter) 3TNV70/76 Model Total Effective 2TNV70(VM) Lube oil capacity 3TNV70(VH/VM) (oil pan) 2.2.1.(3)

  • Page 129: Engine Body

    11. Service Standards 11.2 Engine Body 11.2.1 Cylinder head (1) Cylinder head Inspection item Standard Limit Reference page Combustion surface distortion 0.05 or less 0.15 4.2.5.(1) Intake 0.4 0.6 Valve sink mm Exhaust 0.4 0.6 Intake Seat angle Deg. Valve seat 4.2.6.

  • Page 130: Gear Train And Camshaft

    11. Service Standards 11.2.2 Gear train and camshaft (1) Camshaft Inspection item Standard Limit Reference page Side gap 0.05 0.15 0.25 4.3.4 Bending (1/2 the dial gage reading) 0 0.02 0.05 4.3.5(1) Cam height 34.135 34.265 33.89 Shaft outside diameter / Metal inside diameter Bushing inside diameter 40.000 40.075 40.150...

  • Page 131: Cylinder Block

    11. Service Standards 11.2.3 Cylinder block (1) Cylinder block Inspection item Standard Limit Reference page 2/3TNV70 70.010 70.020 70.200 Cylinder inside diameter 3TNV76 76.010 76.020 76.200 4.4.5.(1) Roundness Cylinder bore 0.01 or less 0.03 Cylindricity (2) Crankshaft Inspection item Standard Limit Reference page Bending (1/2 the dial gauge reading)
  • Page 132 11. Service Standards (4) Piston and ring Piston Inspection item Standard Limit Reference page Piston outside diameter 2/3TNV70 69.960 69.990 69.915 (Measure in the direction 3TNV76 75.955 75.985 75.910 vertical to the piston pin.) Piston diameter measure position 2/3TNV70 22 25 (Upward from the bottom 3TNV76 4.4.5.(4)

  • Page 133: Lubricating Oil System (Trochoid Pump)

    11. Service Standards (5) Connecting rod Inspection item Standard Limit Reference page Thrust clearance 0.2 0.4 4.4.4 Rod small end Item Standard Limit Reference page Bushing inside diameter 22.025 22.038 22.068 Pin outside diameter 21.991 22.000 21.963 4.4.5.(5) Clearance 0.025 0.047 0.105 (6) Tappet Inspection item...

  • Page 134: Tightening Torque For Bolts And Nuts

    12. Tightening Torque for Bolts and Nuts 12. Tightening Torque for Bolts and Nuts 12.1 Tightening Torques for Main Bolts and Nuts Lube oil Thread diameter Tightening torque application Reference Part and engine model pitch (thread portion, and page N m(kgf m) seat surface) 53.9 57.9 Cylinder head bolt...

  • Page 135: Tightening Torques For Standard Bolts And Nuts

    12. Tightening Torque for Bolts and Nuts 12.2 Tightening Torques for Standard Bolts and Nuts Nominal thread diameter Tightening torque Item Remarks pitch Nm(kgf-m) 9.8 11.8 Use 80% of the value at left M6 1 (1.0 1.2) when the tightening part is aluminum.
  • Page 136 Printed in Japan September 2003...

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