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Yanmar 2TR17 Engine

The Yanmar 2TR17 is a heavy-duty, vertical, two-cylinder, liquid-cooled four-stroke diesel engine engineered primarily for agricultural applications, most notably powering vintage utility tractors such as the Yanmar YM1700. Characterized by its robust cast-iron cylinder block and head assembly, this naturally aspirated power unit belongs to Yanmar’s legacy multi-cylinder series renowned for its operational reliability, high torque efficiency, and durable mechanical architecture. It features a compact overall footprint combined with a split-crankcase design optimized for long-term industrial serviceability.

The engine utilizes an overhead valve (OHV) configuration actuated by a single gear-driven camshaft located within the cylinder block. Mechanical pushrods and rocker arm assemblies actuate two valves per cylinder (one intake, one exhaust) mounted vertically in the cylinder head. Valve clearance adjustments are performed via standard mechanical adjustment screws positioned on the rocker arms. Cylinder Bore: 85 mm (3.346 inches). Piston Stroke: 90 mm (3.543 inches). Total Displacement: 1021 cc (1.0 Liter / 62.31 cubic inches).

Fuel System: The fuel delivery infrastructure relies on an inline mechanical injection pump assembly timed directly to the engine's camshaft gear train. Fuel is fed from the primary tank through a sediment bowl filter to the high-pressure injection pump. The pump meters and delivers pressurized fuel to individual mechanical fuel injection valves (injectors) tasked with spraying atomized fuel directly into the combustion zones. Engine RPM and throttle response are controlled by an integrated mechanical flyweight governor built directly into the injection pump drive casing.

Lubrication System: Lubrication is managed via a full-pressure feed system driven by an internal oil pump linked directly to the main gear train. Pressurized engine oil is forced through an integrated oil channel network in the cylinder block to supply the main bearings, connecting rod journals, and overhead valve train. The system incorporates a replaceable oil filter cartridge and a spring-loaded pressure relief valve to regulate system pressure during cold starts and high-RPM operation.

Cooling System: The cooling setup consists of a forced liquid-circulation loop managed by a front-mounted water pump driven via the external accessory belt system. Coolant is drawn from the lower radiator section, forced through the cooling jackets surrounding the cylinder walls and head channels, and returned via a top-mounted thermostat housing. The system utilizes a mechanical thermostat to modulate coolant bypass pathways, ensuring optimal thermal management and preventing localized overheating under load.

General Technical Data

Engine Specifications

Engine Model ............... Yanmar 2TR17
Engine Type ............... 4-cycle vertical inline 2-cylinder water-cooled diesel
Number of Cylinders ............... 2
Cylinder Arrangement ............... In-line, vertical
Engine Bore, in (mm) ............... 3.346 (85.0)
Engine Stroke, in (mm) ............... 3.543 (90.0)
Displacement, cu.in (cc) ............... 62.31 (1021)
Rated Engine Power, hp (kW) ............... 17.0 (12.7)
Rated Engine Speed, rpm ............... 2400
Maximum No-Load Speed, rpm ............... 2600
Minimum Idle Speed, rpm ............... 800
Aspiration Type ............... Naturally aspirated
Combustion System ............... Swirl pre-combustion chamber type
Compression Ratio ............... 21.0:1
Firing Order ............... 1-2
Direction of Rotation ............... Counter-clockwise viewed from flywheel side
Cylinder Block Material ............... High-strength cast iron
Cylinder Head Material ............... High-strength alloy cast iron
Cylinder Liner Type ............... Dry type sleeve
Lubrication System ............... Forced pressure circulation by trochoid pump
Oil Pump Type ............... Gear-driven trochoid pump
Oil Filter Type ............... Full-flow, spin-on
Cooling System ............... Forced liquid circulation by centrifugal water pump
Air Cleaner Type ............... Oil bath or dry multi-stage element configuration
Starting System ............... Electric starter motor actuation
Electrical System, V ............... 12
Charging System ............... Alternator integrated with flywheel regulator

Fuel System

Fuel Injection Pump Type ............... Bosch type NC in-line jerk injection pump
Number of Injection Pump Plungers ............... 2
Injection Pump Plunger Diameter, in (mm) ............... 0.236 (6.0)
Injection Pump Plunger Stroke, in (mm) ............... 0.275 (7.0)
Fuel Injection Nozzle Type ............... Throttle type nozzle structure
Fuel Injection Nozzle Holder ............... Flange mounted dual bolt type
Injection Valve Opening Pressure, psi (MPa) ............... 2275-2417 (15.7-16.7)
Fuel Injection Timing, deg ............... 20.0 BTDC
Fuel Delivery Feed Pump Type ............... Mechanical diaphragm type pump
Governor System Type ............... Mechanical centrifugal all-speed governor
Fuel Filter Assembly Type ............... Spin-on element with sediment bowl
Fuel Filter Micron Rating, um ............... 5.0
Maximum Fuel Suction Head, ft (m) ............... 3.28 (1.0)
Fuel Grade ............... ASTM D975 Number 2-D diesel oil fuel
Maximum Allowable Fuel Inlet Temperature, F (C) ............... 122.0 (50.0)
Injection Pipe Internal Diameter, in (mm) ............... 0.078 (2.0)
Injection Pipe External Diameter, in (mm) ............... 0.236 (6.0)
Governor Idle Spring Constant, lb/in (N/mm) ............... 11.4 (2.0)
Governor Main Spring Constant, lb/in (N/mm) ............... 142.7 (25.0)
Minimum Fuel Line Internal Diameter, in (mm) ............... 0.315 (8.0)
Injection Pump Camshaft End Play, in (mm) ............... 0.0019-0.0059 (0.05-0.15)
Injection Pump Plunger Clearance Limit, in (mm) ............... 0.00019 (0.005)
Nozzle Needle Valve Lap Fit Clearance, in (mm) ............... 0.00007 (0.002)
Fuel System Total Deaeration Volume, cu.in (cc) ............... 4.57 (75.0)

Dimensions and Weight

Overall Length, in (mm) ............... 23.4 (595)
Overall Width, in (mm) ............... 18.9 (480)
Overall Height, in (mm) ............... 26.0 (660)
Dry Weight, lbs (kg) ............... 320 (145)
Wet Weight, lbs (kg) ............... 340 (154)

Maintenance Data

Service Information

Minimum Compression Pressure, psi (MPa) ............... 398.0 (2.74)
Oil Pressure at Rated Speed, psi (MPa) ............... 42.6-56.8 (0.29-0.39)
Oil Pressure at Low Idle Speed, psi (MPa) ............... 11.3 (0.07)
Thermostat Opening Temperature, F (C) ............... 167.0 (75.0)
Thermostat Full Open Temperature, F (C) ............... 194.0 (90.0)
Drive Fan Belt Tension Deflection, in (mm) ............... 0.393-0.590 (10.0-15.0)
Intake Valve Clearance (Cold), in (mm) ............... 0.0078 (0.20)
Exhaust Valve Clearance (Cold), in (mm) ............... 0.0078 (0.20)

Engine Oil and Coolant

Engine Oil Type .................. SAE 30, SAE 10W-30, or SAE 5W-20
API Service Classifications ......................... CC, CD or higher
Engine Oil Capacit, Pan Only, qt (L) ............... 3.17 (3.0)
Engine Oil Capacity with Filter, qt (L) ............... 3.70 (3.5)
Cooling System Capacity, gal (L) ............... 1.18 (4.5)

Service Intervals

Change oil and filter ............... Every 200 hours
Inspect air cleaner ............... Every 50 hours
Replace air cleaner ............... Every 500 hours
Replace fuel filter ............... Every 300 hours
Valve clearance adjustment ............... Every 400 hours
Fuel system inspection ............... Every 400 hours
Change coolant ............... Every 1000 hours
Compression test ............... Every 600 hours
Clean radiator core ............... Every 200 hours
Inspect belt tension ............... Every 100 hours

Service Specifications

Cylinder Liner Bore Inside Diameter, in (mm) ............... 3.3464-3.3476 (85.000-85.030)
Cylinder Liner Out-of-Roundness, in (mm) ............... 0.0003 (0.010)
Crankshaft Main Journal Outside Diameter, in (mm) ............... 2.1641-2.1647 (54.970-54.985)
Crankshaft Main Bearing Clearance, in (mm) ............... 0.0014-0.0030 (0.038-0.078)
Crankpin Outside Diameter, in (mm) ............... 1.8885-1.8891 (47.970-47.985)
Connecting Rod Big End Bearing Clearance, in (mm) ............... 0.0014-0.0029 (0.038-0.075)
Crankshaft Axial End Play, in (mm) ............... 0.0051-0.0090 (0.130-0.230)
Piston Skirt Outside Diameter, in (mm) ............... 3.3429-3.3437 (84.910-84.930)
Piston Skirt to Cylinder Liner Clearance, in (mm) ............... 0.0027-0.0047 (0.070-0.120)
Piston Pin Bore Bushing Inner Diameter, in (mm) ............... 0.9842-0.9846 (25.000-25.012)
Piston Pin Outside Diameter, in (mm) ............... 0.9839-0.9842 (24.992-25.000)
Piston Pin to Con Rod Bushing Clearance, in (mm) ............... 0.0003-0.0007 (0.008-0.020)
Top Ring Groove Width, in (mm) ............... 0.0787-0.0795 (2.000-2.020)
Second PRing Groove Width, in (mm) ............... 0.0787-0.0795 (2.000-2.020)
Oil Ring Groove Width, in (mm) ............... 0.1574-0.1582 (4.000-4.020)
Top Ring Side Clearance, in (mm) ............... 0.0027-0.0041 (0.070-0.105)
Second Ring Side Clearance, in (mm) ............... 0.0019-0.0033 (0.050-0.085)
Oil Ring Side Clearance, in (mm) ............... 0.0011-0.0025 (0.030-0.065)
Top Ring End Gap, in (mm) ............... 0.0098-0.0157 (0.250-0.400)
Second Ring End Gap, in (mm) ............... 0.0078-0.0137 (0.200-0.350)
Oil Ring End Gap, in (mm) ............... 0.0078-0.0137 (0.200-0.350)
Cylinder Head Bottom Deck Distortion Warp, in (mm) ............... 0.0019 (0.050)
Intake Valve Stem Outside Diameter, in (mm) ............... 0.3133-0.3141 (7.960-7.980)
Exhaust Valve Stem Outside Diameter, in (mm) ............... 0.3129-0.3137 (7.950-7.970)
Intake Valve Guide Inner Diameter, in (mm) ............... 0.3153-0.3161 (8.010-8.030)
Exhaust Valve Guide Inner Diameter, in (mm) ............... 0.3153-0.3161 (8.010-8.030)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0015-0.0031 (0.040-0.080)
Intake Valve Seat Width, in (mm) ............... 0.0472-0.0590 (1.200-1.500)
Exhaust Valve Seat Width, in (mm) ............... 0.0472-0.0590 (1.200-1.500)
Intake Valve Recess Depth, in (mm) ............... 0.0236-0.0354 (0.600-0.900)
Exhaust Valve Recess Depth, in (mm) ............... 0.0236-0.0354 (0.600-0.900)
Valve Margin Thickness, in (mm) ............... 0.0393 (1.000)
Valve Spring Free Length, in (mm) ............... 1.6259 (41.300)
Camshaft Journal Outside Diameter (Front), in (mm) ............... 1.6523-1.6531 (41.970-41.990)
Camshaft Journal Outside Diameter (Rear), in (mm) ............... 1.5736-1.5744 (39.970-39.990)
Camshaft Housing Bearing Clearance, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Cam Lobe Height (Intake), in (mm) ............... 1.3523-1.3543 (34.350-34.400)
Cam Lobe Height (Exhaust), in (mm) ............... 1.3523-1.3543 (34.350-34.400)
Rocker Arm Shaft Outer Diameter, in (mm) ............... 0.5492-0.5500 (13.950-13.970)
Rocker Arm Bushing Inner Diameter, in (mm) ............... 0.5511-0.5523 (14.000-14.030)
Rocker Arm Bushing to Shaft Clearance, in (mm) ............... 0.0011-0.0031 (0.030-0.080)
Tappet Lifter Body Outside Diameter, in (mm) ............... 0.4712-0.4720 (11.970-11.990)
Tappet Bore Inside Diameter, in (mm) ............... 0.4724-0.4731 (12.000-12.018)
Tappet Body to Block Bore Clearance, in (mm) ............... 0.0003-0.0018 (0.010-0.048)
Idler Gear Shaft Outside Diameter, in (mm) ............... 1.4555-1.4562 (36.970-36.990)
Idler Gear Bushing Inside Diameter, in (mm) ............... 1.4570-1.4582 (37.010-37.040)
Idler Gear Bushing to Shaft Clearance, in (mm) ............... 0.0007-0.0027 (0.020-0.070)

Tightening Torques

Cylinder Head Nuts (Stage One), lb-ft (Nm) ............... 21.6 (29.4)
Cylinder Head Nuts (Stage Two), lb-ft (Nm) ............... 43.3 (58.8)
Cylinder Head Nuts (Stage Three), lb-ft (Nm) ............... 54.2-57.8 (73.5-78.4)
Connecting Rod Cap Screws, lb-ft (Nm) ............... 28.9-32.5 (39.2-44.1)
Crankshaft Main Bearing Cap Nuts, lb-ft (Nm) ............... 57.8-65.0 (78.4-88.2)
Flywheel Mounting Attachment Bolts, lb-ft (Nm) ............... 54.2-61.4 (73.5-83.3)
Crankshaft Front Nose Drive Pulley Bolt, lb-ft (Nm) ............... 65.0-72.3 (88.2-98.0)
Camshaft Drive Timing Gear Bolt, lb-ft (Nm) ............... 43.3-50.6 (58.8-68.6)
Idler Timing Gear Support Bolt, lb-ft (Nm) ............... 21.6-25.3 (29.4-34.3)
Rocker Arm Shaft Support Bracket Nut, lb-ft (Nm) ............... 21.6-25.3 (29.4-34.3)
Valve Lash Adjustment Screw, lb-ft (Nm) ............... 10.8-14.4 (14.7-19.6)
Rocker Valve Cover Sealed Cap Nuts, lb-ft (Nm) ............... 5.0-7.2 (6.8-9.8)
Injection Pump Housing Body Mounting Nuts, lb-ft (Nm) ............... 14.4-18.0 (19.6-24.5)
Injection Nozzle Holder Clamp Flange Nuts, lb-ft (Nm) ............... 14.4-18.0 (19.6-24.5)
Injection Nozzle Retaining Cap Nut, lb-ft (Nm) ............... 28.9-36.1 (39.2-49.0)
High Pressure Fuel Line Injection Pipe Flare Nut, lb-ft (Nm) ............... 18.0-21.6 (24.5-29.4)
Fuel Delivery Feed Pump Flange Mounting Nuts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Oil Pump Housing Mount Bolts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Oil Sump Pan Peripheral Retention Bolts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Oil Sump Bottom Fluid Drain Hex Plug, lb-ft (Nm) ............... 36.1-43.3 (49.0-58.8)
Oil Filter Threaded Center Spud Core Insert, lb-ft (Nm) ............... 18.0-25.3 (24.5-34.3)
Water Pump Housing Mounting Bolts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Thermostat Outbound Outlet Housing Top Cover Bolts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Radiator Cooling Fan Assembly Pulley Screws, lb-ft (Nm) ............... 5.0-7.2 (6.8-9.8)
Exhaust Manifold Structural Thermal Stud Nuts, lb-ft (Nm) ............... 18.0-21.6 (24.5-29.4)
Intake Manifold Assembly Mount Bolts, lb-ft (Nm) ............... 14.4-18.0 (19.6-24.5)
Starter Motor Flange Chassis Mount Bolts, lb-ft (Nm) ............... 28.9-36.1 (39.2-49.0)
Alternator Pivot Mount Bracket Positioning Bolt, lb-ft (Nm) ............... 14.4-21.6 (19.6-29.4)
Alternator Tension Link Slider Adjustment Locker Bolt, lb-ft (Nm) ............... 10.8-14.4 (14.7-19.6)
Flywheel Housing Rear Adapter Block Frame Bolts, lb-ft (Nm) ............... 36.1-43.3 (49.0-58.8)
Timing Gear Case Outer Front Cover Bolts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Crankcase Breather Air Separator Assembly Screws, lb-ft (Nm) ............... 3.6-5.0 (4.9-6.8)
Glow Plug Element, lb-ft (Nm) ............... 10.8-14.4 (14.7-19.6)
Oil Pressure Switch Indicator Sensor Unit, lb-ft (Nm) ............... 10.8-14.4 (14.7-19.6)
Coolant Water Temperature Sensor Unit , lb-ft (Nm) ............... 14.4-21.6 (19.6-29.4)
Engine Support Foot Bracket To Block Boss Bolts, lb-ft (Nm) ............... 36.1-43.3 (49.0-58.8)
Main Crankcase Split Line Internal Bolts, lb-ft (Nm) ............... 18.0-21.6 (24.5-29.4)
Injection Pump Delivery Valve Spring Caps, lb-ft (Nm) ............... 25.3-28.9 (34.3-39.2)
Fuel Injection Pump Camshaft Bearing Cover Screws, lb-ft (Nm) ............... 5.0-7.2 (6.8-9.8)
Fuel Bleed Screw Air Vent Plug, lb-ft (Nm) ............... 3.6-5.0 (4.9-6.8)
Governor Housing Cover Plate Mounting Screws, lb-ft (Nm) ............... 5.0-7.2 (6.8-9.8)
Governor Weight Assembly Shaft Nut, lb-ft (Nm) ............... 21.6-25.3 (29.4-34.3)
Decompression Lever Axis Shaft Bolts, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Oil Suction Strainer Pipe Flange Block Screws, lb-ft (Nm) ............... 7.2-10.8 (9.8-14.7)
Oil Main Gallery Distribution End Core Plugs, lb-ft (Nm) ............... 18.0-25.3 (24.5-34.3)
Coolant Jacket Expansion Core Plugs, lb (N) ............... 1124.0 (5000.0)
Alternator Wire Terminal Stud Output Nut, lb-in (Nm) ............... 17.7-26.5 (2.0-3.0)
Starter Solenoid Battery Positive Cable Contact Nut, lb-ft (Nm) ............... 5.0-7.2 (6.8-9.8)
Intake Manifold Element Threaded Shell Mounting Nut, lb-ft (Nm) ............... 14.4-18.0 (19.6-24.5)
Exhaust Pipe Flange Connecting Coupling Nuts, lb-ft (Nm) ............... 21.6-25.3 (29.4-34.3)

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• Yanmar Engines Specs
  
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• Yanmar 2TR15 Specs
  
• Yanmar 2TR16 Specs
  
• Yanmar 2TR20A Specs
  

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