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Kohler CV490S Engine

General Technical Data

Kohler CV490S Engine Specifications

Engine Model .......... Kohler Command CV490S
Engine Type .......... Gasoline, vertical shaft, four-cycle
Number of Cylinder .......... Single
Piston Displacement, cc (cu.in) .......... 490 (29.9)
Engine Bore, mm (in) .......... 90.0 (3.60)
Engine Stroke, mm (in) .......... 77.0 (3.03)
Engine Power, Hp (kW) .......... 17.0 (12.7)
Maximum Torque, Nm (ft-lb) .......... 37.8 (27.9)
Fast Idle Speed, rpm .......... 2400
Low Idle Speed, rpm .......... 1400
Compression Ratio .......... 8.5:1
Cooling System .......... Air Intake
Air Cleaner .......... Replaceable, high density paper element

Fuel System

Fuel System Type .......... Carburetor
Carburetor Type .......... Float Fixed Main Jet
Carburetor Model .......... Walbro or Nikki
Fuel Pump .......... Diaphragm Type Mechanical Pump
Fuel Filter .......... In-line
Governor .......... Centrifugal Mechanical Flyweight
Fuel Capacity, L (qt) .......... 7.6 (7.8)

Lubrication System

Lubrication System Type .......... Full-Pressure
Oil Pump Type .......... Gerotor
Oil Filter .......... Full-flow
Oil Capacity, L (qt) .......... 1.9 (2.0)

Electrical System

Electrical System Rating, Volts .......... 12
Ignition System Type .......... Electronic with Spark Advance
Spark Plug .......... Champion RC12YC
Spark Plug Thread Size, mm (in) .......... 14 (0.55)
Spark Plug Reach, mm (in) .......... 19.1 (0.75)
Spark Plug Gap, mm (in) .......... 0.76 (0.030)
Ignition Module Air Gap, mm (in) .......... 0.200-0.300 (0.008-0.012)
Spark Plug Torque, Nm .......... 24.4-29.8
Recommended Battery .......... 12V-250CCA

Dimensions

Length, mm (in) .......... 463 (18.2)
Width, mm (in) .......... 375 (14.8)
Height, mm (in) .......... 321 (12.7)
Dry weight, kg (lbs) .......... 41.9 (90)

Kohler Command CV490S Maintenance Data

Fuel Type (min. octane) .......... 87 Octane Unleaded
Engine oil type .......... SAE 5W-20/5W-30
Engine oil capacity, L (qts) .......... 1.9 (2.0)
Oil filter change interval .......... Every 130 hours
Oil change interval .......... Every 100 hours
Fuel filter change interval .......... Every 100 hours
Spark plug change interval .......... Every 200 hours

Kohler CV490S Service Specifications

Cylinder Bore

Cylinder Bore I.D (Std) .......... 90.000-90.025 mm (3.5433-3.5443 in.)
Cylinder Bore I.D (Maximum Wear Limit) .......... 90.063 mm (3.5458 in.)
Cylinder Bore I.D (Max. Out-of-Round) .......... 0.12 mm (0.0047 in.)
Cylinder Bore I.D (Max. Taper) .......... 0.05 mm (0.0020 in.)

Cylinder Head and Valves

Cylinder Head (Max. Out-of-Flatness) .......... 0.076 mm (0.003 in.)
Hydraulic Valve Lifter to Crankcase Running Clearance .......... 0.0124-0.0501 mm (0.0005-0.0020 in.)
Intake Valve Stem-to-Valve Guide Running Clearance .......... 0.038-0.076 mm (0.0015-0.0030 in.)
Exhaust Valve Stem-to-Valve Guide Running Clearance .......... 0.050-0.088 mm (0.0020-0.0035 in.)
Intake Valve Guide I.D (Std) .......... 7.038-7.058 mm (0.2771-0.2779 in.)
Intake Valve Guide I.D (Maximum Wear Limit) .......... 7.134 mm (0.2809 in.)
Exhaust Valve Guide I.D (Std) .......... 7.038-7.058 mm (0.2771-0.2779 in.)
Exhaust Valve Guide I.D (Maximum Wear Limit) .......... 7.159 mm (0.2819 in.)
Valve Guide Reamer Size (Std) .......... 7.048 mm (0.2775 in.)
Valve Guide Reamer Size (0.25 mm Oversize) .......... 7.298 mm (0.2873 in.)
Intake Valve Minimum Lift .......... 8.96 mm (0.353 in.)
Exhaust Valve Minimum Lift .......... 9.14 mm (0.360 in.)
Nominal Valve Seat Angle .......... 45 deg

Piston, Piston Rings, and Piston Pin

Piston to Piston Pin (selective fit) .......... 0.006-0.017 mm (0.0002-0.0007 in.)
Piston Pin Bore I.D (Std) .......... 19.006-19.012 mm (0.7483-0.7485 in.)
Piston Pin Bore I.D (Maximum Wear Limit) .......... 19.025 mm (0.7490 in.)
Piston Pin O.D (Std) .......... 18.995-19.000 mm (0.7478-0.7480 in.)
Piston Pin O.D (Maximum Wear Limit) .......... 18.994 mm (0.74779 in.)
Top Compression Ring to Groove Side Clearance .......... 0.060-0.105 mm (0.0023-0.0041 in.)
Middle Compression Ring to Groove Side Clearance .......... 0.040-0.085 mm (0.0015-0.0033 in.)
Oil Control Ring to Groove Side Clearance .......... 0.036-0.186 mm (0.0014-0.0073 in.)
Top Compression Ring End Gap Bore .......... 0.28-0.51 mm (0.011-0.020 in.)
Center Compression Ring End Gap Bore .......... 0.22-0.48 mm (0.008-0.018 in.)
Oil Control Ring End Gap .......... 0.250-0.760 mm (0.0098-0.0299 in.)
Piston Thrust Face O.D (Std) .......... 89.951-89.969 mm (3.5413-3.5420 in.)
Piston Thrust Face O.D (Maximum Wear Limit) .......... 89.824 mm (3.5363 in.)
Piston Thrust Face to Cylinder Bore Running Clearance .......... 0.031-0.043 mm (0.0012-0.0016 in.)

Rocker Arm

Rocker Arm I.D (Std) .......... 15.837-16.127 mm (0.63-0.64 in.)
Rocker Arm I.D (Maximum Wear Limit) .......... 16.13 mm (0.640 in.)
Rocker Shaft O.D (Std) .......... 15.90-15.85 mm (0.63 in.)
Rocker Shaft O.D (Maximum Wear Limit) .......... 15.727 mm (0.619 in.)

Crankshaft

Crankshaft End Play (free) .......... 0.0575-0.4925 mm (0.0022-0.0193 in.)
Crankshaft End Play (thrust bearing with shims) .......... 0.050-0.530 mm (0.0020-0.0209 in.)
Crankshaft Bore in Crankcase I.D (Std) .......... 44.965-44.990 mm (1.7702-1.7712 in.)
Crankshaft Bore in Crankcase (Maximum Wear Limit) .......... 44.9758-45.0012 mm (1.7707-1.7717 in.)
Crankshaft Bore in Crankcase Running Clearance (Std) .......... 0.0300-0.0770 mm (0.0011-0.0030 in.)
Crankshaft Bore in Oil Pan I.D (Std) .......... 41.965-42.003 mm (1.6521-1.6536 in.)
Crankshaft Bore in Oil Pan I.D (Maximum Wear Limit) .......... 41.9760-42.0141 mm (1.6526-1.6541 in.)
Crankshaft Bore in Oil Pan Running Clearance (Std) .......... 0.0300-0.0880 mm (0.0011-0.0034 in.)
Flywheel End Main Bearing Journal O.D (Std) .......... 44.913-44.935 mm (1.7682-1.7691 in.)
Flywheel End Main Bearing Journal O.D (Maximum Wear Limit) .......... 44.84 mm (1.765 in.)
Flywheel End Main Bearing Journal (Max. Taper) .......... 0.022 mm (0.0009 in.)
Flywheel End Main Bearing Journal (Max. Out-of-Round) .......... 0.025 mm (0.0010 in.)
Oil Pan End Main Bearing Journal O.D (Std) .......... 41.915-41.935 mm (1.6502-1.6510 in.)
Oil Pan End Main Bearing Journal O.D (Maximum Wear Limit) .......... 41.86 mm (1.648 in.)
Oil Pan End Main Bearing Journal (Max. Taper) .......... 0.020 mm (0.0008 in.)
Oil Pan End Main Bearing Journal (Max. Out-of-Round) .......... 0.025 mm (0.0010 in.)
Connecting Rod Journal O.D (Std) .......... 38.958-30.970 mm (1.5338-1.5343 in.)
Connecting Rod Journal O.D (Maximum Wear Limit) .......... 38.94 mm (1.5328 in.)
Connecting Rod Journal (Max. Taper) .......... 0.012 mm (0.0005 in.)
Connecting Rod Journal (Max. Out-of-Round) .......... 0.025 mm (0.0010 in.)
Crankshaft PTO End, Crank in Engine .......... 0.30 mm (0.012 in.)
Crankshaft Entire Crank, in V-Blocks .......... 0.10 mm (0.0039 in.)

Balance Shaft

Balance Shaft End Play .......... 0.0575-0.3625 mm (0.0027-0.0137 in.)
Balance Shaft Running Clearance .......... 0.0250-0.1520 mm (0.0009-0.0059 in.)
Balance Shaft Bore I.D (Std) .......... 20.000-20.025 mm (0.7874-0.7884 in.)
Balance Shaft Bore I.D (Maximum Wear Limit) .......... 20.038 mm (0.7889 in.)
Balance Shaft Bearing Surface O.D (Std) .......... 19.962-19.975 mm (0.7859-0.7864 in.)
Balance Shaft Bearing Surface (Maximum Wear Limit) .......... 19.959 mm (0.7858 in.)

Camshaft

Camshaft End Play (free) .......... 0.088-0.393 mm (0.003-0.015 in.)
Camshaft End Play End Play (with shims) .......... 0.076-0.127 mm (0.003-0.005 in.)
Camshaft Running Clearance .......... 0.025-0.105 mm (0.0010-0.0041 in.)
Camshaft Bore I.D (Std) .......... 20.000-20.025 mm (0.7874-0.7884 in.)
Camshaft Bore I.D (Maximum Wear Limit) .......... 20.038 mm (0.7889 in.)
Camshaft Bearing Surface O.D (Std) .......... 19.962-19.975 mm (0.7859-0.7864 in.)
Camshaft Bearing Surface O.D (Maximum Wear Limit) .......... 19.959 mm (0.7858 in.)

Connecting Rod

Connecting Rod to Crankpin Running Clearance (Std) .......... 0.030-0.055 mm (0.0012-0.0022 in.)
Connecting Rod to Crankpin Running Clearance (Maximum Wear Limit) .......... 0.07 mm (0.0025 in.)
Connecting Rod to Crankpin Side Clearance .......... 0.18-0.41 mm (0.007-0.016 in.)
Connecting Rod to Piston Pin Running Clearance .......... 0.015-0.028 mm (0.0006-0.0011 in.)
Piston Pin End I.D (Std) .......... 19.015-19.023 mm (0.7486-0.7489 in.)
Piston Pin End I.D (Maximum Wear Limit) .......... 19.036 mm (0.7495 in.)

Governor

Governor Cross Shaft to Crankcase Running Clearance .......... 0.025-0.075 mm (0.0010-0.0030 in.)
Governor Cross Shaft O.D (Std) .......... 5.975-6.000 mm (0.2352-0.2362 in.)
Governor Cross Shaft O.D (Maximum Wear Limit) .......... 5.962 mm (0.2347 in.)
Governor Gear Shaft to Governor Gear Running Clearance .......... 0.050-0.160 mm (0.0019-0.0063 in.)
Governor Gear Shaft O.D (Std) .......... 5.990-6.000 mm (0.2358-0.2362 in.)
Governor Gear Shaft (Maximum Wear Limit) .......... 5.977 mm (0.2353 in.)
Governor Cross Shaft Bore I.D (Std) .......... 6.025-6.050 mm (0.2372-0.2382 in.)
Governor Cross Shaft Bore I.D (Maximum Wear Limit) .......... 6.063 mm (0.2387 in.)

Tightening Torque Specs

Cylinder Head (2 increments) .......... 20, 40.7 Nm (15, 30 ft-lb.)
Rocker Pedestal .......... 11.3 Nm (100 in-lb.)
Fuel Bowl Retaining Screw .......... 5.1-6.2 Nm (45-55 in-lb.)
Starter Mounting Screw .......... 15.3 Nm (135 in-lb)
Fan .......... 9.9 Nm (88 in-lb)
Flywheel Retaining Screw .......... 66.4 Nm (49 ft-lb)
Fuel Pump .......... 9.0 Nm (80 in-lb)
Spark Plug .......... 24.4-29.8 Nm (18-22 ft-lb.)
Ignition Module .......... 6.2 Nm (55 in-lb.)
Muffler Retaining Nuts .......... 24.4 Nm (216 in-lb.)
Oil Filter .......... 10.4-12.7 Nm (90-110 in-lb.)
Oil Pan .......... 24.4 Nm (216 in-lb.)
Oil Pump Cover .......... 6.2 Nm (55 in-lb.)
Governor Control Lever .......... 9.9 Nm (88 in-lb.)
Valve Cover .......... 10.7 Nm (95 in-lb.)
Rocker Arm Screw .......... 11.3 Nm (100 in-lb.)
Rocker Arm Pivot Stud Torque .......... 11.3 Nm (100 in-lb.)
Connecting Rod (6 mm straight shank bolt) .......... 11.3 Nm (100 in-lb.)
Connecting Rod (8 mm step-down bolt) .......... 14.7 Nm (130 in-lb.)
Connecting Rod (8 mm straight shank bolt) .......... 22.7 Nm (200 in-lb.)