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Kohler Command PRO CV640

General Technical Data

Kohler CV640 Engine Specifications

Engine Model ................... Kohler Command PRO CV640
Engine Type ................... 4-cycle OHV V-Twin cylinder air-cooled gasoline
Number of Cylinders ................... 2
Displacement, cc (cu.in) ................... 674 (41.1)
Cylinder Bore, mm (in) ................... 80.0 (3.15)
Piston Stroke, mm (in) ................... 67.0 (2.64)
Rated Engine Power, hp (kW) ................... 20.5 (15.3)
Rated Engine Speed, rpm ................... 3600
Maximum Torque, Nm (ft-lbs) ................... 47.1 (34.7)
Torque Speed, rpm ................... 2400
Compression Ratio ................... 8.5:1
Lubrication System ................... Full pressure
Oil Filter Type ................... Full-flow
Air Cleaner Type ................... Replaceable, paper element
Oil Capacity, L (qts) ................... 1.9 (2.0)
Electrical System Rating, Volts ................... 12
Starter Type ................... Electric
Battery Rating ................... 12V, 400 CCA

Fuel System

Fuel System Type ................... Carburetor
Carburetor Model ................... Nikki or Keihin
Carburetor Type ................... Fixed main jet
Fuel Pump Type ................... Pulse
Fuel Filter Type ................... In-line
Governor Type ................... Mechanical, centrifugal

Dimensions and Weight

Overall Length, mm (in) ................... 452 (17.8)
Overall Width, mm (in) ................... 451 (17.7)
Overall Height, mm (in) ................... 358 (14.1)
Net Weight, kg (lbs) ................... 41.0 (90.0)

Kohler CV640 Maintenance Data

Engine Oil

Engine Oil Type (Summer) ................... SAE 10W-30
Engine Oil Type (Winter) ................... SAE 5W-20, 5W-30
Oil Classification (API Service) ................... SG, SH, SJ or higher
Oil Capacity (w/o Filter), L (qts) ................... 1.7 (1.8)
Oil Capacity (with New Filter), L (qts) ................... 1.9 (2.0)

Carburetor Adjustments

Main Fuel ................... Not adjustable
Idle Fuel ................... Not adjustable
Low Idle Speed, rpm ................... 1200±75
High Idle Speed, rpm ................... 3600±50

Ignition System

Spark Plug Type ................... Champion RC12YC
Spark Plug Gap, mm (in) ................... 0.76 (0.030)
Module Air Gap, mm (in) ................... 0.28-0.33 (0.011-0.013)
Thread Size, mm (in) ................... 14 (0.55)
Reach, mm (in) ................... 19.1 (0.75)

Service Intervals

Service Precleaner Element ................... Every 25 hours
Replace Air Cleaner Element ................... Every 100 hours
Change Engine Oil ................... Every 100 hours
Clean Oil Cooler Fins ................... Every 100 hours
Check Carburetor Adjustment ................... Every 100 hours
Check Spark Plug Gap ................... Every 200 hours
Change Oil Filter ................... Every 200 hours
Replace Spark Plug ................... Every 300 hours
Check and Adjust Valve Clearance ................... Every 300 hours

Kohler CV640 Service Specifications

Cylinder Block

Cylinder Bore I.D (Std) ................... 80.000-80.025 mm (3.1496-3.1506 in.)
Cylinder Bore I.D (Wear Limit) ................... 80.065 mm (3.1522 in.)
Cylinder Bore (Max Out of Round) ................... 0.12 mm (0.0047 in.)
Cylinder Bore (Max Taper) ................... 0.05 mm (0.0020 in.)
Connecting Rod to Crankpin Clearance ................... 0.030-0.055 mm (0.0012-0.0022 in.)
Connecting Rod to Crankpin Side Clearance ................... 0.26-0.63 mm (0.0102-0.0248 in.)
Connecting Rod to Piston Pin Clearance ................... 0.015-0.028 mm (0.0006-0.0011 in.)
Connecting Rod Journal O.D ................... 35.955-35.973 mm (1.4156-1.4163 in.)
Connecting Rod Journal Max Taper ................... 0.018 mm (0.0007 in.)
Crankshaft End Play (Free) ................... 0.070-0.590 mm (0.0028-0.0230 in.)
Crankshaft Bore I.D (Crankcase) ................... 40.965-41.003 mm (1.6128-1.6143 in.)
Crankshaft to Sleeve Bearing Clearance ................... 0.03-0.09 mm (0.0012-0.0035 in.)
Crankshaft Bore I.D (Oil Pan) ................... 40.987-40.974 mm (1.6136-1.6131 in.)
Crankshaft Bore to Crankshaft Clearance ................... 0.039-0.074 mm (0.0015-0.0029 in.)
Crankshaft Bearing Journal O.D (Flywheel) ................... 40.913-40.935 mm (1.6107-1.6116 in.)
Crankshaft Bearing Journal Max Taper (Flywheel) ................... 0.022 mm (0.0009 in.)
Crankshaft Bearing Journal O.D (Oil Pan) ................... 40.913-40.935 mm (1.6107-1.6116 in.)
Crankshaft Bearing Journal Max Taper (Oil Pan) ................... 0.022 mm (0.0009 in.)

Cylinder Head and Valves

Cylinder Head (Max Out of Flatness) ................... 0.076 mm (0.003 in.)
Hydraulic Valve Lifter to Crankcase Clearance ................... 0.0241-0.0501 mm (0.0009-0.0020 in.)
Intake Valve Stem to Guide Clearance ................... 0.038-0.076 mm (0.0015-0.0030 in.)
Exhaust Valve Stem to Guide Clearance ................... 0.050-0.088 mm (0.0020-0.0035 in.)
Intake Valve Guide I.D ................... 7.038-7.058 mm (0.2771-0.2779 in.)
Exhaust Valve Guide I.D ................... 7.038-7.058 mm (0.2771-0.2779 in.)
Valve Guide Reamer Size (Standard) ................... 7.048 mm (0.2775 in.)
Valve Guide Reamer Size (0.25 mm Oversize) ................... 7.298 mm (0.2873 in.)
Intake Valve Minimum Lift ................... 8.07 mm (0.3177 in.)
Exhaust Valve Minimum Lift ................... 8.07 mm (0.3177 in.)
Camshaft End Play (With Shim) ................... 0.076-0.127 mm (0.0030-0.0050 in.)
Camshaft Clearance ................... 0.025-0.063 mm (0.0010-0.0025 in.)
Camshaft Bore I.D ................... 20.000-20.025 mm (0.7874-0.7884 in.)
Camshaft Bearing Surface O.D ................... 19.962-19.975 mm (0.7859-0.7864 in.)

Piston and Piston Rings

Piston Pin End I.D ................... 17.015-17.023 mm (0.6699-0.6702 in.)
Piston Pin Bore I.D ................... 17.006-17.012 mm (0.6695-0.6698 in.)
Piston Pin O.D ................... 16.995-17.000 mm (0.6691-0.6693 in.)
Piston to Piston Pin Clearance ................... 0.006-0.017 mm (0.0002-0.0007 in.)
Top Ring Groove Clearance ................... 0.030-0.076 mm (0.0012-0.0030 in.)
Second Ring Groove Clearance ................... 0.030-0.076 mm (0.0012-0.0030 in.)
Oil Ring Groove Clearance ................... 0.046-0.196 mm (0.0018-0.0077 in.)
Top Ring End Gap ................... 0.18-0.46 mm (0.0071-0.0181 in.)
Second Ring End Gap ................... 0.18-0.46 mm (0.0071-0.0181 in.)
Piston Thrust Face O.D ................... 79.963-79.979 mm (3.1481-3.1488 in.)

Tightening Torque Specs

Cylinder Head Flange Nut ................... 16.9-33.9 Nm (12.5-25 ft-lbs)
Cylinder Head Bolt ................... 22.6-41.8 Nm (16.7-30.8 ft-lbs)
Rocker Arm Screw ................... 11.3 Nm (8.3 ft-lbs)
Connecting Rod Cap ................... 22.7 Nm (16.7 ft-lbs)
Flywheel Retaining Screw ................... 66.4 Nm (49 ft-lbs)
Intake Manifold Mounting ................... 7.4 Nm (5.5 ft-lbs)
Carburetor Mounting Nut ................... 6.2-7.3 Nm (4.6-5.4 ft-lbs)
Oil Drain Plug ................... 13.6 Nm (10 ft-lbs)
Oil Pan Screw ................... 24.4 Nm (18 ft-lbs)
Governor Lever Nut ................... 6.8 Nm (5 ft-lbs)
Ignition Module ................... 4.0-6.2 Nm (2.9-4.6 ft-lbs)
Spark Plug ................... 24.4-29.8 Nm (18-22 ft-lbs)
Oil Filter Screw ................... 10.4-12.7 Nm (7.5-9.2 ft-lbs)