Kubota WG1605-E3 Workshop Manual
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Kubota WG1605-E3 Workshop Manual

Kubota WG1605-E3 Workshop Manual

Gasoline, lpg, natural gas engine
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WORKSHOP MANUAL
GASOLINE, LPG,
NATURAL GAS ENGINE
WG1605-E3
KiSC issued 03, 2022 A

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Summary of Contents for Kubota WG1605-E3

  • Page 1 WORKSHOP MANUAL GASOLINE, LPG, NATURAL GAS ENGINE WG1605-E3 KiSC issued 03, 2022 A...
  • Page 2 All illustrations, photographs and specifications contained in this manual are of the newest information available at the time of publication. Kubota reserves the right to change all information at any time without notice. Since this manual includes many models, information or illustrations and photographs can show more than one model.
  • Page 3 Added the information about adjusting a fan belt tension. 2-15 2-18 3-29 Improved the procedure of measuring compression pressure. 3-36 Corrected the word related to maintenance interval of the following item. • Cleaning of spark plug 2-15 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 4 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 5: Table Of Contents

    3. Cylinder number ............................2-4 4. Catalytic muffler / converter ........................2-4 GENERAL PRECAUTIONS ..........................2-5 MAINTENANCE CHECK LIST........................... 2-7 CHECK AND MAINTENANCE......................... 2-11 1. Daily check points........................... 2-11 1.1 Checking engine oil level ........................ 2-11 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 6 5. Bushing replacing tool ..........................2-28 6. Flywheel stopper ............................2-29 7. Crankshaft bearing 1 replacing tool ......................2-29 8. Governor gear holder bushing replacing tool ..................2-29 9. Crank sleeve setter..........................2-30 3. ENGINE MECHANISM ..............................3-1 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 7 6.2.3 Engine control unit (ECU) ....................... 3-23 6.2.4 Water temperature sensor ...................... 3-23 6.2.5 Temperature and manifold absolute pressure sensor (Tmap sensor) ........3-23 6.2.6 Crankshaft position sensor ..................... 3-23 6.2.7 Camshaft position sensor ....................... 3-24 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 8 4.3.1 Cylinder head and valves ....................... 3-63 4.3.2 Timing gear and camshaft ...................... 3-69 4.3.3 Piston and connecting rod ...................... 3-72 4.3.4 Crankshaft ..........................3-75 4.3.5 Cylinder...........................3-79 4.3.6 Oil pump ..........................3-80 4.3.7 Starter .............................3-81 4.3.8 Alternator ..........................3-83 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 9: Information

    INFORMATION KiSC issued 03, 2022 A...

  • Page 10: Safety First

    • Do not do the procedures below when you start the engine. – Short across starter terminals – Bypass the safety start switch • Do not make unauthorized modifications to the engine. This can cause damage and decrease the engine life. WG1605-E3 KiSC issued 03, 2022 A...

  • Page 11: Operate Safely

    Only remove a closed area. The exhaust gas contains poisonous the radiator cap when it is at a sufficiently low carbon monoxide. temperature to touch with bare hands. Slowly WG1605-E3 KiSC issued 03, 2022 A...

  • Page 12: Discard Fluids Correctly

    8. Prevent acid burns • Keep electrolyte away from your eyes, hands and clothing. Sulfuric acid in battery electrolyte is poisonous and it can burn your skin and clothing and cause blindness. WG1605-E3 KiSC issued 03, 2022 A...
  • Page 13  SAFETY FIRST 1. INFORMATION   WG1605-E3 KiSC issued 03, 2022 A...

  • Page 14: Specifications

    12 V, 480 W, 720 W Fuel *Unleaded automobile gasoline Commercial LPG Lubricating oil Better than SL Class (API) SAE 10W-30 Lubricating oil capacity 6.0 L (1.6 U.S.gals) Catalytic muffler/Converter Three way catalyst (Continued) WG1605-E3 KiSC issued 03, 2022 A...
  • Page 15 *The specification described above is of the standard engine of each model. *Conversion formula: HP = 0.746 kW, PS = 0.7355 kW *Kubota recommended LPG fuel specifications • Commercial propane gas only. • Equivalent to propanes H-D-5 of GPA* standards.

  • Page 16: Specification For Wg1605-Gl-E3

    Three way catalyst Weight (Dry) 121 kg (267 lbs) Application General power source NOTE *The specification described above is of the standard engine of each model. *Conversion formula: HP = 0.746 kW, PS = 0.7355 kW WG1605-E3 KiSC issued 03, 2022 A...
  • Page 17  SPECIFICATIONS 1. INFORMATION   *Kubota recommended LPG fuel specifications • Commercial propane gas only. • Equivalent to propanes H-D-5 of GPA* standards. Others ≥ 90 % ≤ 5 % ≤ 2.5 % － (vol %) *GPA • Gas processors association (U.S.A.)

  • Page 18: Specification For Wg1605-N-E3, Wg1605-Ln-E3

    Charging alternator 12 V, 480 W, 720 W Fuel Natural gas Commercial LPG Lubricating oil Better than SL class (API) SAE 10W-30 Lubricating oil capacity 6.0 L (1.6 U.S.gals) Catalytic muffler/Converter Three way catalyst (Continued) WG1605-E3 KiSC issued 03, 2022 A...
  • Page 19 Natural gas fuel LPG fuel Weight (Dry) 120 kg (265 lbs) NOTE *The specification described above is of the standard engine of each model. *Conversion formula: HP = 0.746 kW, PS = 0.7355 kW 1-10 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 20: Specification For Wg1605-Gln-E3

    Charging alternator 12 V, 480 W, 720 W Fuel *Unleaded automobile gasoline Natural gas Commercial LPG Lubricating oil Better than SL class (API) SAE 10W-30 Lubricating oil capacity 6.0 L (1.6 U.S.gals) (Continued) 1-11 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 21  SPECIFICATIONS 1. INFORMATION   WG1605-GLN-E3 Model Gasoline Natural gas fuel LPG fuel Catalytic muffler / Converter Three way catalyst Weight (Dry) 120 kg (265 lbs) Application General power source 1-12 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 22: Important Items Of Exhaust Emission Regulation

    Japan 19 ≤ P < 560 HC / 0.6 g / kWh, NO /0.6 g / kWh, CO / 20 g / kWh 19 < P None with evaporative emission regulation See figure 1-13 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 23: Three-Way Catalyst

    NO to N near the stoichiometric ratio. Kubota supplies a certified catalyst. FEA must use a The main basic component of an exhaust gas Kubota certified catalyst and assemble the exhaust purification system that uses a three-way catalyst is system parts according to the instructions.

  • Page 24: Performance Curves

     PERFORMANCE CURVES 1. Performance curve for WG1605-G-E3, WG1605-L-E3, WG1605-GL-E3, WG1605-N-E3 1. INFORMATION PERFORMANCE CURVES 1. Performance curve for WG1605-G-E3, WG1605-L-E3, WG1605-GL- E3, WG1605-N-E3 1-15 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 25 (6) Gross intermittent brake (a) Gasoline use (2) Engine speed (5) Gross intermittent torque horsepower (b) LP gas use (3) Specific fuel consumption (7) Gross intermittent specific fuel (c) Natural gas use consumption 1-16 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 26: Dimensions

     DIMENSIONS 1. Dimension for WG1605-G-E3 1. INFORMATION DIMENSIONS 1. Dimension for WG1605-G-E3 1-17 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 27: Dimension For Wg1605-L-E3, Wg1605-N-E3, Wg1605-Ln-E3

     DIMENSIONS 1. INFORMATION 2. Dimension for WG1605-L-E3, WG1605-N-E3, WG1605-LN-E3 2. Dimension for WG1605-L-E3, WG1605-N-E3, WG1605-LN-E3 1-18 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 28: Dimension For Wg1605-Gl-E3, Wg1605-Gln-E3

     DIMENSIONS 3. Dimension for WG1605-GL-E3, WG1605-GLN-E3 1. INFORMATION 3. Dimension for WG1605-GL-E3, WG1605-GLN-E3 1-19 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 29  DIMENSIONS 1. INFORMATION   1-20 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 30: Wiring Diagram

     WIRING DIAGRAM   1. INFORMATION WIRING DIAGRAM 1-21 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 31: Wiring Diagram For Wg1605-G-E3

     WIRING DIAGRAM 1. INFORMATION 1. Wiring diagram for WG1605-G-E3 1. Wiring diagram for WG1605-G-E3 1-22 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 32: Wiring Diagram For Wg1605-L-E3, Wg1605-N-E3, Wg1605-Ln-E3

     WIRING DIAGRAM 2. Wiring diagram for WG1605-L-E3, WG1605-N-E3, WG1605-LN-E3 1. INFORMATION 2. Wiring diagram for WG1605-L-E3, WG1605-N-E3, WG1605-LN-E3 1-23 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 33: Wiring Diagram For Wg1605-Gl-E3, Wg1605-Gln-E3

     WIRING DIAGRAM 1. INFORMATION 3. Wiring diagram for WG1605-GL-E3, WG1605-GLN-E3 3. Wiring diagram for WG1605-GL-E3, WG1605-GLN-E3 1-24 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 34: General

    GENERAL KiSC issued 03, 2022 A...

  • Page 35: Engine Identification

    The engine serial number is an identification number for the engine. It is marked after the engine model name. (2) Engine serial number It indicates the engine series, the production year and month, and the lot number. WG1605-E3 KiSC issued 03, 2022 A...
  • Page 36 2024 2025 2026 (a) WG1605: Engine model (d) U: Production month (Octo- name ber) 2027 (b) 1: Engine series (WG1605 (e) 0001: Lot number (0001～ series) 9999 or A001～Z999) (c) C: Production year (2012) WG1605-E3 KiSC issued 03, 2022 A...

  • Page 37: E3 Engine

    Phase 3 #KBXB####### When servicing or repairing ###-E3 series engines, use only replacement parts for that specific E3 engine, designated by the appropriate E3 Kubota parts list and perform maintenance services listed appropriate Kubota operator's manual or in the appropriate E3 Kubota workshop manual.

  • Page 38: Cylinder Number

    [A] Catalytic muffler (3) Catalyst lot number 4 digits [B] Catalytic converter The cylinder numbers of KUBOTA gasoline, gasoline / Kubota provides the catalytic muffler and converter as LPG and natural gas engine are designated as shown the catalyst parts.

  • Page 39: General Precautions

    Screws, bolts and nuts should be replaced in their original position to prevent reassembly errors. • When special tools are required, use Kubota genuine special tools. Special tools which are not frequently used should be made according to the drawings provided.
  • Page 40   2. GENERAL   WG1605-E3 KiSC issued 03, 2022 A...

  • Page 41: Maintenance Check List

    To keep long-lasting and safe engine performance, make it a rule to do regular inspections by following the table below. (The schedule applies to an engine in use under normal conditions.) CAUTION • When changing or inspecting, be sure to level and stop the engine. WG1605-E3 KiSC issued 03, 2022 A...
  • Page 42   2. GENERAL   [WG1605-E3] Service interval Every Every Every Every Item 50 hrs Every Every Every Every Every 　8 hrs 1000 hr 2000 hr (Week- 100 hrs 200 hrs 500 hrs 1 year 2 years (Daily) Checking engine oil level ☆...
  • Page 43 ★ Change engine oil and replace oil filter cartridge after the first 50 hours of operation. Change more often when operating under dusty conditions. If you do not have the proper tools and / or are not mechanically proficient, contact your local KUBOTA dealer. WG1605-E3...
  • Page 44   2. GENERAL   2-10 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 45: Check And Maintenance

    (1) Dipstick 3. Check to see that the oil level lies between the two notches. 4. If the level is too low, add new oil to the specified level. 2-11 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 46: Checking Air Cleaner Element (If Necessary)

    1. Remove the dust cup in the air cleaner. 2. Check the dust in the dust cup and the element. 1.5 Checking LPG / natural gas tank setting condition (If necessary) WG1605-L-E3, WG1605-GL-E3 2-12 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 47: Checking Lpg / Natural Gas Fuel Connector

    • Use the proper SAE engine oil according to • To prevent serious damage to the engine, ambient temperature. replacement element must be highly efficient. Use only a Kubota genuine filter or its SAE30 or SAE10W-30 or equivalent. Above 25 ℃ (77 ℉) SAE15W-40 1.

  • Page 48: Check Points Of Every 50 Hours

    3. After the fuel hose and the clamp have been replaced, make sure that there is no fuel leakage. (1) Clamp (2) Fuel hose 3.2 Checking LPG / natural gas fuel hose and clamp bands WG1605-L-E3, WG1605-N-E3, WG1605-GL-E3, WG1605-LN-E3, WG1605-GLN-E3 2-14 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 49: Check Points Of Every 100 Hours

    / nut 7.24 to 8.33 lbf⋅ft 4.3 Checking fuel filter CAUTION • Stop the engine when trying to check and clean the fuel filter. • Gasoline fuel is extremely flammable, so avoid fires. 2-15 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 50: Checking Fan Belt Damage And Wear

    Deflection (B) (A) Good (B) Bad cation (Under load of 98 N (10 kgf, 22 lbf)) 4. If the fan belt is nearly worn out and deeply sunk in the pulley groove, replace it. 2-16 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 51: Check Points Of Every 200 Hours

    • Be sure to stop engine before changing engine • To prevent serious damage to the engine, oil. replacement element must be highly efficient. Use only a Kubota genuine filter or its IMPORTANT equivalent. • When using an oil of different maker or viscosity from the previous one, remove all of 1.

  • Page 52: Check Points Of Every 500 Hours

    (Mass per 1 rib 1 m of belt) Width (Number of ribs) Measure at location (A) in the figure with (L) as the distance Span L between the fan drive pulley and alternator pulley. 2-18 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 53: Check Points Of Every 1000 Hours

    Tools required • Feeler gauge 1. Remove the cylinder head cover. (1) Coolant hose (2) LPG/natural gas tank 2. If the coolant hose is damaged, replace it. 2-19 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 54: Check Points Of Every 2000 Hours

    2. Remove the spark plug (1). Adjustable cylinder location of pis- Intake Exhaust valve valve ☆ ☆ When No. 1 piston is at ☆ compression top dead ☆ center. (1) Spark plug 3. Replace the new spark plug. 2-20 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 55: Check Points Of Every 1 Year

    3 minutes after stopping the engine. • Remove the hose after covering the hose with a waste to prevent scatter of fuel. 1. Replace the fuel filter (1) with a new one. 2-21 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 56 6. After flushing, fill with clean water and anti-freeze until the coolant level is just below the port. Install the radiator cap (1) correctly. 7. Fill with the coolant up to [FULL] (A) mark on the reserve tank (4). 2-22 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 57: Check Points Of Every 2 Years

    10.3 Replacing LPG / natural gas fuel hose and clamp bands WG1605-L-E3, WG1605-N-E3, WG1605-GL-E3, WG1605-LN-E3, WG1605-GLN-E3 1. Replace the fuel hose and the clamps. 2-23 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 58: Replacing Coolant Hose Of Lpg/Natural Gas Vaporizer

    (2). 2. Replace lockoff valve filter (5), magnet (3), seal (4) and O-rings (6). 3. Reassemble lockoff valve filter (5), magnet (3) , seal (4), O-rings (6) and the filter chamber (2). 2-24 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 59: Changing Radiator Coolant (L.l.c.)

    • Use clean, fresh, soft water and anti-freeze to fill the radiator and recovery tank. • When the anti-freeze is mixed with fresh, soft water, the anti-freeze mixing ratio must be less than 50 %. • Securely tighten radiator cap. 2-25 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 60 NOTE • The above data represents industrial standards that necessitate a minimum glycol content in the concentrated anti-freeze. 2-26 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 61: Special Tools

    • This special tool is not provided, so make it by referring to the figure. (1) Gauge (5) Adaptor 2 (2) Cable (6) Adaptor 3 (3) Threaded joint (7) Adaptor 4 (4) Adaptor 1 (8) Adaptor 5 Code No. 07916-32032 2-27 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 62: Bushing Replacing Tool

    20 mm dia. (0.79 in. dia.) Chamfer 2.0 mm (0.079 in.) 6.3 μm (250 μin.) C0.3 Chamfer 0.3 mm (0.01 in.) 6.3 μm (250 μin.) Material SS400 Chamfer 1.0 mm (0.039 in.) Chamfer 2.0 mm (0.079 in.) 2-28 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 63: Flywheel Stopper

    NOTE • The special tools are not provided, so make them referring to the figure. [Press out] 135 mm (5.31 in.) 72 mm (2.8 in.) 40 mm radius (1.6 in. radius) (Continued) 2-29 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 64: Crank Sleeve Setter

    12 mm (0.47 in.) 30 mm (1.2 in.) M10 × Pitch 1.25 2.0 mm (0.079 in.) 10 mm (0.39 in.) [A] Auxiliary socket for pushing 2.0 mm (0.079 in.) 130 mm (5.12 in.) (Continued) (Continued) 2-30 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 65  SPECIAL TOOLS   2. GENERAL 17.90 to 17.95 mm dia. (0.7048 to 0.7066 in. dia.) 8.0 mm dia. (0.31 in. dia.) 1.8 mm (0.071 in.) 0.09 rad (5°) C0.5 Chamfer 0.5 mm (0.02 in.) 2-31 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 66  SPECIAL TOOLS 2. GENERAL   2-32 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 67: Engine

    ENGINE KiSC issued 03, 2022 A...

  • Page 68: Mechanism

    The cross-flow type intake / exhaust ports, which lower charge. the heat conduction from the exhaust port to the intake port. The low heat conduction keeps the intake air from being heated and expanded by the exhaust gas. WG1605-E3 KiSC issued 03, 2022 A...

  • Page 69: Combustion System

    (crankshaft bearing 1) (1), the intermediate journal by a split type (crankshaft bearing 3) (4), and the rear by a split type (crankshaft bearing 2) (6) with thrust bearings (5). (1) Combustion chamber (3) Second ring (2) Top ring (4) Oil ring WG1605-E3 KiSC issued 03, 2022 A...

  • Page 70: Connecting Rod

    (5) Pin to open and close them. (3) Camshaft stopper 1.9 Gear shaft The gear shaft is a shaft that was changed from the fuel camshaft for 05-E3B engine to the shaft with no cam. WG1605-E3 KiSC issued 03, 2022 A...

  • Page 71: Inlet And Exhaust Valves

    The flywheel has gear teeth around its outer rim, which mesh with the drive pinion of the starter. Also, a rotor for determining the ignition timing is attached to the flywheel. WG1605-E3 KiSC issued 03, 2022 A...

  • Page 72: Lubricating System

    • Full pressure feed type • Pressure feed and splash type KUBOTA engines have lubricating system of full pressure feed type. This system consists of an oil strainer (11), oil pump (12), relief valve (10), oil filter cartridge (9) and oil pressure switch (2).

  • Page 73: Oil Pump

    This allows the other lobes to slide over the outer lobes, making a seal to prevent back-up of oil. As the lobes slide up and over the lobes on the outer rotor (2), WG1605-E3 KiSC issued 03, 2022 A...

  • Page 74: Relief Valve

    It may also impair the physical and chemical properties of the oil itself. The lubricating oil which is force-fed by the pump, is filtered by the filter cartridge with the filter element (2). WG1605-E3 KiSC issued 03, 2022 A...

  • Page 75: Cooling System

    69.5 to 72.5 ℃ Thermostat's valve opening temperature Service specification 157.1 to 162.5 ℉ (1) Radiator (3) Cooling fan (5) Cylinder head (2) Water pump (4) Thermostat (6) Cylinder block WG1605-E3 KiSC issued 03, 2022 A...

  • Page 76: Water Pump

    As the coolant temperature rises, the wax in the pellet (3) turns liquid and expands, repelling the spindle, which causes the pellet to lower. The valve (2) opens to send the coolant to the radiator. (1) Tube (A) Cooling air (2) Fin WG1605-E3 KiSC issued 03, 2022 A...

  • Page 77: Radiator Cap

    When the coolant temperature falls and a vacuum forms in the radiator, the vacuum valve (2) opens to introduce the air into the radiator. (1) Pressure valve (Opening (2) Vacuum valve pressure 88 kPa (0.90 kgf/cm , 13 psi)) 3-10 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 78: Fuel System

    The LPG/natural gas fuel is evaporated in vaporizer (9) and is sent to the regulator (7) as a gaseous fuel of gas pressure near the atmospheric pressure. The regulator (7) mixes the gas and air is supplied in the cylinder. WG1605-GL-E3, WG1605-GLN-E3 This fuel system has 2 ways (gasoline fuel and LPG/natural gas fuel). 3-11 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 79: Fuel Filter (Wg1605-G-E3, Wg1605-Gl-E3, Wg1605-Gln-E3)

    (11) LPG/natural gas manual (b) Bleed/return circuit Component Marked * is Not (5) Gasoline tank valve (c) Gaseous propane or natural Provided by KUBOTA (6) Mixer (12) LPG/natural gas tank gas line (7) Regulator (D-EPR) (13) Coolant hose 4.2 Fuel filter (WG1605-G-E3,...

  • Page 80: Electronic Throttle Body (Etb)

    The ECU uses the fuel temperature and pressure, to calculate the precise amount of gasoline, to be injected to the engine during operation. The manifold is designed into the system, to control 3-13 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 81: Injectors And Delivery Pipe (Wg1605-G-E3, Wg1605-Gl-E3, Wg1605-Gln-E3)

    When the engine is cranking or running, a partial vacuum is created in the fuel line, which connects the regulator to the direct electronic pressure regulators (DEPR), and mixer. This partial vacuum opens the second stage regulator, permitting fuel to flow to the DEPR, and mixer. 3-14 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 82 (20) Coolant fitting housing retain- (25) Secondary cover (9) Heat exchanger (15) Primary cover ing screw (10) Coolant gasket (16) Primary diaphragm (21) Secondary chamber (11) Primary pin (17) Primary spring (22) Secondary seat 3-15 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 83: Lock Off Valve (Wg1605-L-E3, Wg1605-N-E3, Wg1605-Ln-E3, Wg1605-Gln-E3)

    KUBOTA engines have two kinds of catalytic devices, catalytic muffler and catalytic converter. 3-16 WG1605-E3...

  • Page 84: Oxygen Sensor

    As a result, a more compact and lightweight starter other way around, resulting in a significant drop in the design has been achieved. electromotive force near the stoichiometric ratio. That is, the feedback control functions as electronic control 3-17 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 85 When the pinion gear engages with the ring gear at a When the engine starts, the clutch idles to prevent the certain position, the magnetic switch main contact ring gear from driving the armature in reverse. 3-18 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 86: Starter Switch

    The roller will switch. function as a wedge between the inner and outer, and As the standard part of KUBOTA engine, the starter will transmit the rotation of the outer to the inner,and switch in below figure is recommended.

  • Page 87: Starter Safety System

    IC regulator has no moving parts. 2. Since IC regulator has over-temperature compensation property, which makes the control voltage low if the temperature is increased, it makes it possible to properly charge the batteries. 3-20 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 88 Because of this, it is required to conduct the action called rectification so that the alternating current can be changed to direct current. Alternator conducts rectification by means of diode. 3-21 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 89 P terminal waveform: The alternator P terminal outputs rotation signals required by a tachometer, and so on. The P terminal corresponds with one phase of the alternator stator and the output waveform during power 3-22 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 90: Engine Control Unit (Ecu)

    As well, the ECU will provide diagnostic control, over the fuel system. 6.2.6 Crankshaft position sensor The Crankshaft Position Sensor provides engine speed information. 3-23 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 91: Camshaft Position Sensor

    ECU. When the ECU receives the voltage change, the ECU will slightly retard the timing, until such time, the knocking no longer exists. 3-24 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 92: Servicing

    5. Improper input signal to ECU Check the wire harness – Deficient output 1. Improper intake or exhaust Replace 3-66 valve sealing 2. Improper valve clearance Adjust 3-36 3. Piston ring and cylinder worn Replace 3-73 3-79 (Continued) 3-25 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 93 3-43 2. Damaged spark plug Adjust spark plug or replace 2-15 3. Wires disconnected or dam- Reconnect / replace – aged wire 4. Bad connection of ignition coil Reconnect – and spark plug 3-26 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 94: Troubleshooting For Gasoline Fuel

    Probable cause Solution ence page Engine turns over at normal 1. No fuel Fill fuel – speed but does not start 2.Damaged fuel system Check fuel line and electronic – throttle body and repair 3-27 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 95: Troubleshooting For Lpg / Natural Gas Fuel

    1. Fill LPG / natural gas fuel – idling 2. Check lock off valve Defection output 1. LPG / natural gas density is 1. Repair or replace of fuel sys- – rich or lean 2. Replace vaporizer 3-28 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 96: Service Specifications For Engine

    7.5 kgf/31.0 mm 6.4 kgf/31.0 mm 17 lbf/1.22 in. 14 lbf/1.22 in. Rocker Arm Shaft to Rocker Arm Oil clearance 0.016 to 0.045 mm 0.10 mm 0.00063 to 0.0017 in. 0.0039 in. (Continued) 3-29 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 97 • Idle gear 2 Oil clearance 0.020 to 0.054 mm 0.10 mm 0.00079 to 0.0021 in. 0.0039 in. • Idle gear bushing I.D. 26.000 to 26.021 mm － 1.0237 to 1.0244 in. (Continued) 3-30 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 98 0.0014 to 0.0037 in. 0.0079 in. • Crankshaft journal O.D. 47.934 to 47.950 mm － 1.8872 to 1.8877 in. • Crankshaft bearing 2 I.D. 47.984 to 48.029 mm － 1.8892 to 1.8909 in. (Continued) 3-31 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 99 10 seconds or more － 88 → 59 kPa 0.89 → 0.61 kgf/cm 12 → 8.6 psi Radiator Weak Leakage Test Pressure No leak at specified pressure － (210 kPa, 2.14 kgf/cm , 30.5 psi) 3-32 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 100 Stator (Resistance) Less than － 1.0 Ω Rotor (Resistance) 2.9 Ω － Slip ring (O.D.) 14.4 mm 14.0 mm 0.567 in. 0.551 in. Brush (Length) 10.0 mm 8.4 mm 0.394 in. 0.33 in. 3-33 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 101: Tightening Torque

    7.91 to 9.19 57.2 to 66.5 LPG/natural gas in 19.6 to 39.2 2.00 to 3.99 14.5 to 28.9 － Lock off valve fitting union PT 1/4 11.2 to 12.8 1.15 to 1.30 8.26 to 9.44 3-34 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 102: Tightening Torques For General Use Screws, Bolts

    1.00 to 1.15 7.24 to 8.31 24 to 27 2.4 to 2.8 18 to 20 49 to 55 5.0 to 5.7 37 to 41 78 to 90 7.9 to 9.2 58 to 66 3-35 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 103: Checking, Disassembling, And Servicing

    • If the compression pressure is still less than the service limit, check the top clearance, valve clearance and cylinder head. 3-36 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 104: Lubricating System

    0.145 to 0.185 mm valve clearance • Oil strainer clogged cation 0.00571 to 0.00728 in. (cold) • Oil filter cartridge clogged • Oil gallery clogged • Excessive oil clearance • Foreign matter in the relief valve 3-37 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 105: Cooling System

    (1). NOTE • If the measurement is out of the service specifications, loosen alternator mounting screws and adjust its position. (A) Good (B) Bad 3-38 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 106 1. Set a radiator tester (1) and an adapter (2) on the radiator cap. (A) Radiator tester (B) Adaptor Radiator water Service specifi- No leak at specified pres- leakage test pres- cation sure sure 3-39 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 107: Fuel System

    20 ℃ (68 ℉) (1) Terminal 1 (5) Terminal 5 (2) Terminal 2 (6) Terminal 6 (3) Terminal 3 (4) Terminal 4 5. If the resistance is not with in the service specifications, replace it. 3-40 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 108 • These non-KUBOTA installed parts, such as hoses, fittings, piping, should be approved for LPG / natural gas use and conform to UL, CSA, NFPA, and all other recognized standards.

  • Page 109: Ignition System

    2. Remove the spark plug, put it inside the ignition coil firmly, and then ground the threaded section to the engine body (not to painted or resin parts). 3. Rotate the starter with the key switch and check that the plug sparks. 3-42 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 110 3. If the resistance is not with in the service 3. Replace the plug if the electrode or the insulator is deformed or cracked. specifications, replace it. 4. Tighten the plug with a plug wrench. 3-43 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 111: Electrical System

    • Keep your body and face as far away from the battery when performing maintenance and inspection. • Do not allow people who do not know how to handle a battery or who do not sufficiently understand the danger perform inspection or maintenance. 3-44 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 112 7. If the pinion gear does not pop out, the magnetic 6. Connect a jumper lead momentarily between the switch is failure. Repair or replace the starter. starter's body and the battery negative terminal (3). 3-45 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 113 (77 ℉) 3. If the results of alternator on unit test are not within the specifications, disassemble the alternator and check the each component part for finding out the failure. 3-46 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 114: Disassembling And Assembling

    2. Place an oil pan underneath the engine. 3. Remove the drain plug (1) to drain oil. 4. After draining, screw in the drain plug (1). • Tighten to the specified tightening torque. (2) Dipstick 3-47 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 115: External Components

    (2) Fan belt 3. Remove the alternator. 4. Remove the starter. (When reassembling) (1) Gasoline hose connector IMPORTANT • After reassembling the fan belt (2), be sure to adjust the fan belt tension. 3-48 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 116 (2) Coolant hose 9.81 to 11.3 N⋅m Ignition coil mount- (3) Vaporizer 1.00 to 1.15 kgf⋅m ing screw / nut 7.24 to 8.33 lbf⋅ft (When reassembling) • Bleed the vaporizer after supplying coolant. 3-49 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 117: Cylinder Head, Valves And Oil Pan

    16.0 to 19.5 lbf⋅ft NOTE • Use special screw for the knock sensor. • Install the knock sensor in the direction approximately as shown in the illustration so that no force is applied to the harness. 3-50 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 118 If defect is found, replace tappets. • Before installing the tappets, apply engine oil thinly around them. 4.2.3.5 Removing valves 1. Remove the valve caps (2). 6. Remove the cylinder head gasket. 3-51 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 119 • Visually check the O-ring (4), apply engine oil, and install it. (1) Oil pan (2) Oil pan mounting screw 3. Remove the oil strainer (3). 3-52 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 120: Thermostat

    2. Remove the fan drive pulley screw. 3. Draw out the fan drive pulley with a puller. (When reassembling) • Apply engine oil to the fan drive pulley retaining screws. And tighten it. 3-53 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 121 (3) Cam gear Tools required • Adhesive (Three Bond 1324B or equivalent) 6. Remove the external circlip (11) from the PTO shaft (12). 1. Remove the idle gear 2 (7)/idle gear 1 (4). 3-54 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 122: Piston And Connecting Rod

    • Make sure to assemble the external circlip of the governor shaft. • Check the governor shaft for smooth rotation. 4.2.6.2 Removing piston 1. Turn the flywheel and bring the piston to top dead center. 3-55 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 123 "C" of the top compression ring on the opposite side of the slant portion, and stagger the gaps "A", "E" of the second compression ring and spacer making 2.09 rad (120 °) from the gap of the 3-56 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 124: Crankshaft

    2. Remove all flywheel screws (1) and then remove the flywheel (2). (1) Bearing case cover mount- (a) Top mark "UP" ing screw (Inside) (2) Bearing case cover mount- ing screw (Outside) (1) Flywheel screw (2) Flywheel 3-57 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 125 3 (7). IMPORTANT • Be careful to protect crankshaft bearing 1 from scratches, caused by the crank shaft, etc. 1. Remove the main bearing case screw 2 (1). 3-58 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 126 • Install the main bearing case assemblies in original facing outward. positions. Since diameters of main bearing cases vary, install them in order of marking (b) from the gear case side. (Refer to the figure.) 3-59 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 127: Removing Starter

    5. Remove the through bolts (22), then the rear end frame (13). 6. Remove the brush from the brush holder while holding the spring up. 7. Remove the brush holder (21). 8. Draw out the yoke (19) from the starter drive housing (2). 3-60 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 128 • Apply grease (DENSO.CO.LTD. No. 50 or equivalent) to the parts indicated in the figure. – Joint of solenoid switch (a) – Bushing (b) – Drive lever (c) – Collar (d) – Teeth of pinion gear (e) – Armature shaft (f) 3-61 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 129: Removing Alternator

    8. Press out the rotor (6) from drive end frame (2). 9. Remove the retainer plate (5). 10. Press out the bearing (4) from drive end frame (2) with a press and jig. 3-62 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 130: Servicing

    1.2 to 1.5 mm Top clearance cation 0.048 to 0.059 in. 4.3.1 Cylinder head and valves 4.3.1.1 Measuring top clearance 1. Remove the cylinder head. NOTE • Top clearance Width crushed plastigauge (2). 3-63 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 131 6. If they are out of spec, check the oil clearance of the crank pin, journal and piston pins. 4.3.1.2 Measuring cylinder head surface flatness IMPORTANT • Be sure to check the valve recessing after replacing cylinder head. 3-64 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 132 3. Measure the valve recessing with a depth gauge. 0.050 (protrusion) to 0.25 Service specifi- (recessing) mm Valve recessing cation 0.0020 (protrusion) to (Intake and Ex- 0.0098 (recessing) in. haust) 0.40 (recessing) mm Service limit 0.016 (recessing) in. 3-65 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 133 4. Apply prussian blue to the contact surface to check the seated rate. If it is less than 70 %, repeat valve lapping again. 3-66 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 134 4.3.1.9 Replacing valve guide the way around. IMPORTANT 4.3.1.8 Measuring clearance between valve • Do not hit the valve guide with a hammer during stem and valve guide replacement. Tools required • Outside micrometer 3-67 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 135 1.39 to 1.40 in. Free length (B) 34.8 mm Service limit 1.37 in. 2. Read the compression load on the gauge. 3. If the measurement is less than the service limit, replace it. 3-68 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 136: Timing Gear And Camshaft

    0.00079 to 0.0024 in. tween tappet and 0.07 mm tappet guide bore Service limit 0.003 in. 4.3.2 Timing gear and camshaft 4.3.2.1 Measuring timing gear backlash Tools required • Dial indicator (lever type) 3-69 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 137 2. Set a dial indicator with its tip on the intermediate to the front and rear. journal. Service specifi- 0.20 to 0.51 mm cation 0.0079 to 0.020 in. Idle gear 1 and 2 side clearance 0.80 mm Service limit 0.031 in. 3-70 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 138 0.050 to 0.091 mm cation 0.0020 to 0.0035 in. Oil clearance of camshaft journal 0.15 mm Service limit 0.0059 in. 2. If the measurement is less than the service limit, replace the camshaft. 3-71 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 139: Piston And Connecting Rod

    Service specifi- 22.002 to 22.011 mm Piston pin O.D. cation 0.86622 to 0.86657 in. 3-72 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 140 2. Using a small end bushing replacing tool, press in a new bushing (service parts) taking due care to see that the connecting rod hole matches the bushing hole. 3-73 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 141 2. Measure the clearance between the ring and the 3. Install the connecting rod on the connecting rod groove with a thickness gauge. alignment tool. 4. Put a gauge over the piston pin, and move it against the face plate. 3-74 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 142: Crankshaft

    4. If the same size bearing is useless because of the crankshaft journal wear, replace it with an oversize 4. If the measurement exceeds the service limit, one referring to the table and figure. replace the crankshaft. 3-75 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 143 6. If the same size bearing is useless because of the crank pin wear, replace it with an undersize one referring to the table and figure. (Reference) • Undersize dimensions of crank pin 3-76 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 144 2 (Crankshaft bearing 3) NOTE • Be sure not to move the crankshaft while the bearing case screws are tightened. 1. Put a strip of plastigauge on the center of the journal. 3-77 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 145 5. If the same size bearing is useless because of the crankshaft journal wear, replace it with an undersize one referring to the table and figure. (Reference) • Undersize dimensions of crankshaft journal 3-78 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 146: Cylinder

    1. Measure the I.D. of the cylinder at the 6 positions (see figure) with a cylinder gauge to find the maximum and minimum I.D.'s. Service specifi- 79.000 to 79.019 mm cation 3.1103 to 3.1109 in. Cylinder I.D. 79.15 mm Service limit 3.116 in. 3-79 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 147: Oil Pump

    1. Measure the clearance between lobes of the inner rotor and the outer rotor with a feeler gauge. 2. If the clearance exceeds the service specifications, replace the oil pump rotor assembly. 3-80 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 148: Starter

    O.D.'s 0.4 mm Service limit 0.02 in. 1. Check the contact of the commutator for wear, and grind the commutator with emery paper if it is 5. Measure the mica undercut. slightly worn. 3-81 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 149 3. If the length is less than the service limit, replace the yoke assembly and brush holder. Service specifi- 16.0 mm cation 0.630 in. Brush length (A) 10.5 mm Service limit 0.413 in. 4. If it does not conduct, replace the armature. 3-82 WG1605-E3 KiSC issued 03, 2022 A...

  • Page 150: Alternator

    4. If it conducts, replace the yoke assembly. 4.3.8 Alternator 4.3.8.1 Checking alternator bearing 1. Check the bearing for smooth rotation. 4. If infinity is not indicated, replace it. Service specifi- Resistance 2.9 Ω cation 3-83 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 151 2. The rectifier is normal if the diode in the rectifier conducts in one direction and does not conduct in the reverse direction. 2. If the measurement is less than the service limit, replace it. 3-84 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 152 F terminal (1) of IC regulator with resistance range of circuit tester. (1) F terminal (2) B terminal 2. The IC regulator is normal if the conducts in one direction and does not conduct in the reverse direction. 3-85 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 153  SERVICING 3. ENGINE 4. Checking, disassembling, and servicing 3-86 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 154 3-76 measuring height..........3-71 crank sensor cam gear checking resistance........... 3-42 removing............3-54 crank sleeve setter...........2-30 cam sensor crankcase ventilation connections......1-14 checking resistance........... 3-42 crankshaft..............3-2 camshaft..............3-3 alignment............3-75 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 155 (WG1605-GLN-E3)......... 3-13 fuel tank cleaning inside........... 2-21 E3 engine..............2-3 function..............3-19 electronic throttle body (ETB)........3-13 engine service specifications......... 3-29 engine control unit (ECU)........ 1-14,3-23 gaseous fuel system..........1-14 engine model name........... 2-1 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 156 P terminal......3-23 natural gas tank setting condition (if necessary) lock off valve............1-14 checking.............2-12 lock off valve (WG1605-GLN-E3)......3-16 natural gas vaporizer lock off valve (WG1605-L-E3)........3-16 checking.............2-24 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 157 2-27 push rod specification for WG1605-G-E3......... 1-5 removing............3-50 specification for WG1605-GLN-E3......1-11 push rod alignment specification for WG1605-L-E3........1-5 measuring............3-69 Specification of alternator with IC (Incorporated with) regulator.............3-21 start safety..............1-1 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 158 3-18,3-19 replacing............3-67 when the pinion gear engages with the ring gear valve guide replacing tool........2-27 without collision..........3-18 valve lapping wiring diagram adjusting.............3-66 WG1605-G-E3........... 1-22 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 159 WG1605-GL-E3..........1-24 WG1605-GLN-E3..........1-24 WG1605-L-E3............ 1-23 WG1605-LN-E3..........1-23 WG1605-N-E3........... 1-23 WG1605-E3 KiSC issued 03, 2022 A...
  • Page 160 : Engine Service Department Address : 64, Ishizu-Kitamachi, Sakai-Ku, Sakai-City, Osaka, 590-0823, Japan Phone : +81-72-241-1531 : +81-72-245-2928 E-mail : kbt_g.estg-pub@kubota.com Printed in Japan 2022. 03, S, EI, EI, engusa Code No. 9Y111-06616 KUBOTA Corporation 2012. 01, S, EI, EI, engusa...

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