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Yanmar 3TNA72 Engine

General Technical Data

Yanmar 3TNA72 Engine Specifications

Engine Model .......... Yanmar 3TNA72UJ3
Engine Type .......... 3 cylinder diesel, indirect injection
Number of Cylinders .......... Three
Cycle .......... 4
Bore, mm (in.) .......... 72 (2.83)
Stroke, mm (in.) .......... 72 (2.83)
Displacement, L (cu in.) .......... 0.879 (53.64)
Rated Engine Power, kW (hp) .......... 12.7 (17.0)
Maximum Engine Power, kW (hp) .......... 16.4 (22.0)
Maximum Torque, Nm (ft-lb) .......... 47.6 (37)
Torque Speed, rpm .......... 2700
Fast Idle Speed, rpm .......... 3625
Slow Idle Speed, rpm .......... 1450
Compression Ratio - 22.3:1
Firing Order .......... 1-3-2
Combustion System .......... Indirect Injection
Aspiration .......... Natural
Air Cleaner .......... Heavy duty, dry replaceable filter element with cyclone precleaner
Crankshaft Alignment .......... Horizontal

Fuel System

Fuel Injection Pump Minimum Lobe Height .......... 30.90 mm (1.217 in.)
Injection Pump Camshaft Clearance .......... 0.15 mm (0.006 in.)
Injection Pump Camshaft O.D. (Wear Limit) .......... 7.90 mm (0.311 in.)
Separator Plate Injection Nozzle Contact Surface Maximum Wear .......... 0.10 mm (0.0039 in.)
Governor .......... Mechanical
Governor Shaft O.D. (Minimum) .......... 7.90 mm (0.311 in.)
Governor Shaft Bore I.D (Wear Limit) .......... 8.15 mm (0.321 in.)
Governor Shaft Bore Clearance .......... 0.18 mm (0.007 in.)
Governor Shaft Bore Sleeve I.D. (Maximum) .......... 8.20 mm (0.323 in.)

Lubrication System

Lubrication .......... Full pressure to main and connecting rod bearings and governor
Oil Filter .......... Full flow, replaceable
Crankcase Capacity, L (qt) .......... 3.1 (3.3)
Oil Pump Rotor Shaft O.D to Backing Plate I.D. Clearance .......... 0.015-0.048 mm (0.0006-0.0035 in.)
Oil Pump Rotor Recess .......... 0.25 mm (0.010 in.)
Oil Pump Outer Rotor to Pump Body Clearance .......... 0.03-0.09 mm (0.0011-0.0035 in.)
Oil Pump Inner to Outer Rotor Clearance .......... 0.15 mm (0.0059 in.)
Oil Pressure Regulating Valve Spring Compressed Length .......... 14.70 mm (0.580 in.) / 12 N (2.7 lb-force)
Oil Pressure Regulating Valve Spring Free Length .......... 21.90-24.50 mm (0.860-0.960 in.)

Electrical System

Electrical System Rating, Volts .......... 12
Starter .......... Nippondenso, 1.0 kW
Charging System .......... Alternator
Alternator .......... Kokosan, 20A
Battery Voltage .......... 12
Reserve Capacity, min/amp .......... 102/25
Cold Cranking, Amp .......... 491

Dimensions

Width, in (mm) .......... 19.8 (500)
Height, in (mm) .......... 21.7 (550)
Depth, in (mm) .......... 16.7 (423)
Weight, lbs (kg) .......... 280 (130)

Yanmar 3TNA72 Maintenance Data

Engine oil type .......... SAE 10W-30/15W-40
Engine oil capacity, L (qts) .......... 3.1 (3.3)
Coolant capacity, L (qts) .......... 4.7 (5.0)
Oil filter change interval .......... Every 200 hours
Oil change interval .......... Every 200 hours
Fuel filter change interval .......... Every 400 hours

Yanmar 3TNA72 Service Specifications

Cylinder Block

Cylinder Bore Clearance .......... 0.28 mm (0.011 in.)
Cylinder Bore I.D (Std) .......... 72.00-72.03 mm (2.835-2.836 in.)
Cylinder Bore I.D (Wear Limit) .......... 72.20 mm (2.843 in.)
Cylinder Bore I.D (0.25 mm Oversize) .......... 72.25-72.28 mm (2.845-2.846 in.)
Cylinder Bore I.D (0.50 mm Oversize) .......... 72.50-72.53 mm (2.855-2.856 in.)
Crankshaft Maximum Bend .......... 0.02 mm (0.0007 in.)
Connecting Rod Journal O.D (Std) .......... 39.97-39.98 mm (1.5736-1.5740 in.)
Connecting Rod Journal O.D (Wear Limit) .......... 39.92 mm (1.572 in.)
Connecting Rod Bearing Clearance .......... 0.16 mm (0.006 in.)
Connecting Rod Bearing I.D (Std) .......... 40.00-40.042 mm (1.575-1.577 in.)
Connecting Rod Bearing I.D (Wear Limit) .......... 40.07 mm (1.578 in.)
Main Bearing Journal O.D (Std) .......... 43.97-43.98 mm (1.7311-1.7315 in.)
Main Bearing Journal O.D (Wear Limit) .......... 43.92 mm (1.729 in.)
Main Bearing Clearance .......... 0.15 mm (0.0059 in.)
Main Bearing I.D (Std) .......... 44.00-44.042 mm (1.732-1.734 in.)
Main Bearing I.D (Wear Limit) .......... 44.07 mm (1.735 in.)

Rocker Arm

Rocker Arm Shaft O.D (Std) .......... 11.96-11.98 mm (0.4711-0.4718 in.)
Rocker Arm Shaft O.D (Wear Limit) .......... 11.95 mm (0.4706 in.)
Rocker Arm and Shaft Support Clearance .......... 0.14 mm (0.005 in.)
Rocker Arm and Shaft Support I.D (Std) .......... 12.00-12.02 mm (0.4724-0.4732 in.)
Rocker Arm and Shaft Support I.D (Wear Limit) .......... 12.09 mm (0.4759 in.)
Push Rod Length (Std) .......... 141-142 mm (5.550-5.590 in.)
Push Rod Bend (Wear Limit) .......... 0.08 mm (0.003 in.)

Cylinder Head and Valves

Cylinder Head Distortion (Std) .......... 0.05 mm (0.002 in.)
Cylinder Head Distortion (Wear Limit) .......... 0.15 mm (0.006 in.)
Intake Valve Seat Width (Std) .......... 1.44 mm (0.057 in.)
Intake Valve Seat Width (Wear Limit) .......... 1.98 mm (0.078 in.)
Exhaust Valve Seat Width (Std) .......... 1.77 mm (0.070 in.)
Exhaust Valve Seat Width (Wear Limit) .......... 2.27 mm (0.089 in.)
Intake and Exhaust Valves Faces .......... 0.51 mm (0.020 in.)
Exhaust Valve Face Angle .......... 45 deg
Intake Valve Face Angle .......... 30 deg
Valve Stem O.D (Std) .......... 6.94-6.96 mm (0.2732-0.2740 in.)
Valve Stem O.D (Wear Limit) .......... 6.90 mm (0.2717 in.)
Valve Recession (Exhaust/Intake) .......... 0.85 mm (0.033 in.) / 0.50 mm (0.020 in.)
Valve Guide I.D (Maximum Clearance) .......... 0.20 mm (0.008 in.)
Valve Guide I.D (Std) .......... 7.00-7.02 mm (0.275-0.276 in.)
Valve Guide I.D (Wear Limit) .......... 7.08 mm (0.279 in.)
Valve Guide Height .......... 9 mm (0.354 in.)
Valve Springs Free Length (Wear Limit) .......... 37.40 mm (1.472 in.)
Exhaust Valve Seat Angle .......... 45 deg
Intake Valve Seat Angle .......... 30 deg

Pistons and Piston Rings

Piston to Cylinder Head Clearance .......... 0.61-0.79 mm (0.024-0.031 in.)
Piston Ring Groove Clearance (First Compression Ring) .......... 0.075-0.110 mm (0.0030-0.0043 in.)
Piston Ring Groove Clearance (Second Compression Ring) .......... 0.030-0.065 mm (0.0012-0.0026 in.)
Piston Ring Groove Clearance (Oil Ring) .......... 0.020-0.055 mm (0.0008-0.0022 in.)
Piston Ring End Gap (First Compression Ring) .......... 0.10-0.25 mm (0.004-0.010 in.)
Piston Ring End Gap (Second Compression Ring) .......... 0.25-0.40 mm (0.010-0.016 in.)
Piston Ring End Gap (Oil Ring) .......... 0.15-0.35 mm (0.006-0.014 in.)
Piston Pin O.D (Std) .......... 20.991-21.00 mm (0.826-0.827 in.)
Piston Pin O.D (Wear Limit) .......... 20.975 mm (0.825 in.)
Piston Pin Bore Clearance .......... 0.045 mm (0.0018 in.)
Piston Pin Bore I.D (Std) .......... 21.00-21.009 mm (0.8268-0.8271 in.)
Piston Pin Bore I.D (Wear Limit) .......... 21.02 mm (0.828 in.)
Piston Pin Bushing Clearance .......... 0.110 mm (0.0043 in.)
Piston Pin Bushing I.D (Std) .......... 21.025-21.038 mm (0.8278-0.8282 in.)
Piston Pin Bushing I.D (Wear Limit) .......... 21.10 mm (0.831 in.)
Piston O.D (Std) .......... 71.922-71.952 mm (2.832-2.833 in.)
Piston O.D (Wear Limit) .......... 71.81 mm (2.827 in.)
Piston O.D (0.25 mm Oversize) .......... 72.17-72.20 mm (2.841-2.842 in.)
Piston O.D (0.50 mm Oversize) .......... 72.42-72.45 mm (2.851-2.852 in.)

Camshaft

Camshaft Side Gap .......... 0.05-0.15 mm (0.0020-0.0060 in.)
Maximum Camshaft Bend .......... 0.02 mm (0.001 in.)
Lobe Height .......... 33.95-34.05 mm (1.337-1.341 in.)
Camshaft Journal O.D (Gear Housing and Flywheel Ends) .......... 39.94-39.96 mm (1.5724-1.5732 in.)
Camshaft Journal O.D (Intermediate) .......... 39.91-39.94 mm (1.5713-1.5724 in.)
Camshaft Bushing I.D .......... 40.00-40.065 mm (1.575-1.577 in.)
Camshaft Bushing Clearance .......... 0.18 mm (0.007 in.)
Camshaft Bore I.D .......... 40.00-40.025 mm (1.575-1.576 in.)
Cam Followers O.D .......... 20.927-20.960 mm (0.8239-0.8252 in.)
Cam Followers Bore Clearance .......... 0.040-0.094 mm (0.0016-0.0037 in.)
Cam Followers Bore I.D .......... 21.00-21.021 mm (0.8268-0.8276 in.)

Yanmar 3TNA72 Checks and Adjustments

Valve Clearance .......... 0.20 mm (0.008 in.)
Connecting Rod Side Play .......... 0.20-0.40 mm (0.0079-0.0157 in.)
Connecting Rod Bearing Clearance .......... 0.020-0.072 mm (0.0008-0.0028 in.)
Crankshaft End Play .......... 0.090-0.271 mm (0.004-0.011 in.)
Crankshaft Main Bearing Clearance .......... 0.020-0.072 mm (0.0008-0.0028 in.)
Valve Lift (Intake and Exhaust) .......... 7.5 mm (0.300 in.)
Camshaft End Play .......... 0.05-0.20 mm (0.0020-0.0079 in.)
Fuel Injection Nozzle Opening Pressure .......... 11722 ± 480 kPa (1700 ± 70 psi)
Fuel Injection Nozzle Leakage at 11032 kPa (1600 psi) .......... Minimum of 10 Seconds
Thermostat (Begin Opening) .......... 71C (160F)
Thermostat (Fully Open) .......... 85C (184F)
Minimum Lift Height .......... 8 mm (0.310 in.)
Coolant Temperature Sensor Continuity .......... 107-113C (225-235F)

Yanmar 3TNA72 Tightening Torque Specs

Rocker Arm Cover .......... 18 Nm (160 lb-in.)
Rocker Arm Assembly .......... 26 Nm (226 lb-in.)
Cylinder Head .......... 38 Nm (28 lb-ft) .......... 61 Nm (45 lb-ft)
Exhaust Manifold .......... 26 Nm (30 lb-in.)
Intake Manifold .......... 11 Nm (97 lb-in.)
Piston and Connecting Rod .......... 23 Nm (203 lb-in.)
Flywheel Housing/Plate to Extension .......... 49 Nm (36 lb-ft)
Crankshaft Rear Oil Seal Case to Block .......... 11Nm (96 lb-in.)
Crankshaft Bearing .......... 79 Nm (58 lb-ft)
Flywheel .......... 83 Nm (61 lb-ft)
Flywheel Housing/Plate .......... 49 Nm (36 lb-ft)
Camshaft .......... 11 Nm (96 lb-in.)
Timing Gear Cover .......... 9 Nm (78 lb-in.)
Crankcase Extension Housing to Cover .......... 22 Nm (195 lb-in.)
Crankshaft Pulley .......... 115 Nm (85 lb-ft)
Oil Pump .......... 25 Nm (18 lb-ft)
Thermostat Cover .......... 26 Nm (226 lb-in.)
Water Pump .......... 26 Nm (226 lb-in.)
Fan Mounting .......... 11 Nm (96 lb-in.)
Fuel Injection Pump .......... 20 Nm (180 lb-in.)
Fuel Injection Pump Camshaft Bearing Retaining .......... 20 Nm (180 lb-in.)
Fuel Injection Nozzles .......... 40 Nm (30 lb-ft)