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Kohler CV12.5S Engine

General Technical Data

Kohler CV12.5S Engine Specifications

Engine Model .......... Kohler Command CV-12.5S
Engine Type .......... Gasoline, vertical shaft, four-cycle
Number of Cylinder .......... Single
Piston Displacement, cc (cu.in) .......... 398 (24.3)
Engine Bore, mm (in) .......... 87.0 (3.43)
Engine Stroke, mm (in) .......... 67.0 (2.64)
Engine Power, Hp (kW) .......... 12.5 (9.33)
Maximum Torque, Nm (ft-lb) .......... 27.8 (20.5)
Fast Idle Speed, rpm .......... 2500
Low Idle Speed, rpm .......... 1500
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)

Ignition System

Ignition System Type .......... Dependable electronic magneto
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) .......... 1.02 (0.040)
Ignition Module Air Gap, mm (in) .......... 0.200-0.300 (0.0078-0.0118)
Spark Plug Torque, Nm .......... 24.4-29.8

Electrical System

Electrical System Rating, Volts .......... 12
Alternator Charging Capacity, Amp .......... 13
Starting System .......... Retractable starter
Recommended Battery .......... 12V-250CCA

Dimensions

Length, mm (in) .......... 450 (17.7)
Width, mm (in) .......... 365 (14.4)
Height, mm (in) .......... 321 (12.7)
Dry weight, kg (lbs) .......... 39.5 (87)

Kohler Command CV12.5S 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 CV12.5S Service Specifications

Cylinder Block

Cylinder Bore I.D (Std) .......... 87.000-87.025 mm (3.4252-3.4262 in.)
Cylinder Bore I.D (Maximum Wear Limit) .......... 87.063 mm (3.4277 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 and Piston Rings

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 .......... 0.034-0.100 mm (0.0013-0.0039 in.)
Middle Compression Ring to Groove Side Clearance .......... 0.040-0.080 mm (0.0016-0.0032 in.)
Oil Control Ring to Groove Side Clearance .......... 0.036-0.186 mm (0.0014-0.0073 in.)
Top Compression Ring End Gap Bore .......... 0.250-0.500 mm (0.010-0.020 in.)
Center Compression Ring End Gap Bore .......... 0.250-0.510 mm (0.0010-0.020 in.)
Oil Control Ring End Gap .......... 0.250-1.020 mm (0.010-0.040 in.)
Piston Thrust Face O.D (Std) .......... 86.941-86.959 mm (3.4229-3.4236 in.)
Piston Thrust Face O.D (Maximum Wear Limit) .......... 86.814 mm (3.4179 in.)
Piston Thrust Face to Cylinder Bore Running Clearance .......... 0.041-0.044 mm (0.0016-0.0017 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.)

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.)