The Kohler CH1000 is a 999 cc (61.0 cu·in) natural aspirated V-twin four-stroke air-cooled internal combustion small gasoline engine from the Command PRO series with a horizontal shaft, manufactured by Kohler Co for general-purpose applications.
A 90.0 mm (3.54 in) cylinder bore and 78.5 mm (3.09 in) piston stroke give the CH1000 engine a total of 999 cc of displacement. The compression ratio rating is 8.8:1.
The CH1000 engine produced 37.5 PS (27.6 KW; 37.0 HP) at 3,600 rpm of maximum horsepower and 75.0 Nm (7.6 kg·m; 55.3 ft·lb) at 3,400 rpm of maximum torque.
The Kohler CH1000 features:
- OHV design
- Hydraulic valve lifters
- Aluminum cylinder block
- Cast iron cylinder liners
- Extra-large sleeve bearings
- CDI/MDI or Digital Spark Advance Ignition (DSAI) ignition systems
- Two-barrel, side-draft carburetor with fixed main jets
- Mechanical centrifugal governor
- Full pressure lubrication system
- Forced air cooling system
- Electric starter
- 20 amp charging system (15 amp stator with a 25 amp rectifier-regulator)
General information
| Engine Specifications | |
| Engine model | Command PRO CH1000 |
| Engine type | 4-stroke, OHV, V-twin |
| Displacement | 999 cm3, (61.0 cu·in) |
| Max. horsepower | 37.5 PS (27.6 KW; 37.0 HP) at 3,600 rpm 40.5 PS (29.8 KW; 40.0 HP) at 3,600 rpm |
| Max. torque | 75.0 Nm (7.6 kg·m; 55.3 ft·lb) at 3,400 rpm |
| Cooling system | Forced air |
| Air cleaner | High-efficiency, heavy-duty air filters |
| Lubricating system | Full pressure |
| Ignition system | CDI/MDI or Digital Spark Advance Ignition (DSAI) ignition systems |
| Fuel system | Two-barrel, side-draft carburetor with fixed main jets |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Starting system | Electric starter |
| Governor | Mechanical centrifugal governor |
| PTO shaft rotation | Counterclockwise (from PTO shaft side) |
| Dimensions (L x W X H) | 388 x 484 x 699 mm (15.3 x 19.0 x 27.5 in) |
| Dry weight | 59.0 kg (132.0 lbs) |
Cylinder Block and Head
| Cylinder block | |
| Compression ratio: | 8.8:1 |
| Cylinder bore: | 90.0 mm (3.54 in) |
| Piston stroke: | 78.5 mm (3.09 in) |
| Cylinder internal diameter (standard): | 90.000-90.0025 mm (3.5433-3.5434 in) |
| Number of piston rings (compression / oil): | 2/1 |
| Connecting rod big end diameter (standard): | 44.030-44.037 mm (1.7335-1.7337 in) |
| Piston style A | |
| Thrust face outer diameter (standard): | 89.953-89.967 mm (3.5414-3.542 in) |
| Piston pin outer diameter (standard): | 18.995-19.000 mm (0.7478-0.7480 in) |
| Side clearance (Top): | 0.040-0.080 mm (0.0016-0.0031 in) |
| Side clearance (Second): | 0.040-0.080 mm (0.0016-0.0031 in) |
| Side clearance (Oil): | 0.030-0.190 mm (0.0012-0.0075 in) |
| Ring end gap (Top): | 0.300-0.550 mm (0.0118-0.0217 in) |
| Ring end gap (Second): | 0.300-0.550 mm (0.0118-0.0217 in) |
| Piston style B | |
| Thrust face outer diameter (standard): | 89.972 mm (3.5422 in) |
| Piston pin outer diameter (standard): | 19.995-20.000 mm (0.7872-0.7874 in) |
| Side clearance (Top): | 0.030-0.070 mm (0.0010-0.0026 in) |
| Side clearance (Second): | 0.030-0.070 mm (0.0010-0.0026 in) |
| Side clearance (Oil): | 0.060-0.190 mm (0.0022-0.0073 in) |
| Ring end gap (Top): | 0.125-0.304 mm (0.0049-0.0120 in)/td> |
| Ring end gap (Second): | 0.900-1.179 mm (0.0345-0.0464 in) |
| Crankshaft | |
| Crankshaft main journal diameter: | 44.978-45.000 mm (1.7708-1.7717 in) |
| Crankpin journal diameter: | 43.982-44.000 mm (1.7316-1.7323 in) |
| Cylinder head | |
| Valve arrangement: | OHV, gear driven |
| Valves: | 2 (4 valves in total) |
| Valve head diameter (INTAKE): | 38.625-38.685 mm (1.5207-1.523 in) |
| Valve head diameter (EXHAUST): | 31.625-31.825 mm (1.2451-1.253 in) |
| Valve seat angle (INTAKE): | 89° |
| Valve seat angle (EXHAUST): | 89° |
| Valve seat angle (INTAKE): | 45° |
| Valve seat angle (EXHAUST): | 45° |
| Valve steam diameter (INTAKE): | 6.982-7.000 mm (0.2749-0.2756 in) |
| Valve steam diameter (EXHAUST): | 6.970-6.988 mm (0.2744-0.2751 in) |
| Camshaft lobe height (INTAKE): | 34.100 mm (1.3425 in) |
| Camshaft lobe height (EXHAUST): | 35.000 mm (1.378 in) |
| Camshaft journal diameter: | 19.962-19.975 mm (0.7859-0.7864 in) |
Tightening torque specs
| Tightening torque specs | |
| Intake manifold mounting (torque in 2 increments) | Step 1: 16.9 Nm (1.7 kgf·m; 12.5 lb·ft) Step 2: 22.6 Nm (2.3 kgf·m; 16.7 lb·ft) |
| Connecting rod cap | 11.0 Nm (1.1 kgf·m; 8.1 lb·ft) |
| Cylinder head | Bolt (torque in 2 increments): Step 1: 23.7 Nm (2.4 kgf·m; 17.5 lb·ft) Step 2: 46.9 Nm (4.8 kgf·m; 34.6 lb·ft) |
| Fan | 10.4 Nm (1.1 kgf·m; 7.7 lb·ft) |
| Flywheel | 69.8 Nm (7.1 kgf·m; 51.5 lb·ft) |
| Governor lever nut | 7.1 Nm (0.7 kgf·m; 5.2 lb·ft) |
| Muffler retaining nuts | 24.4 Nm (2.5 kg·m; 18.0 ft·lb) |
| Spark plug | 27 Nm (2.75 kg·m; 20.0 ft·lb) |
Service Data
| Engine | |
| Maximum speed: | 3600±50 rpm |
| Idle speed: | 1200±75 rpm |
| Compression pressure | |
| Standard: | 1.1 MPa (160 psi) |
| Compression differential limit between cylinders: | 15% and less |
| Oil system | |
| Lubrication system: | Full pressure |
| Oil type: | API SJ or higher |
| Recommended oil: | SAE 10W-30, KOHLER PRO 10W-50 |
| Oil capacity: | W/o oil filter: 1.9 liters (2.0 US.qts, 1.7 Imp. qts) With oil filter: 2.6 liters (2.75 US.qts, 2.3 Imp. qts) |
| Fuel system | |
| Type: | Two-barrel, side-draft carburetor with fixed main jets |
| Fuel pump: | Pulse style fuel pump or remote-mounted electric fuel pump (optional) |
| Fuel filter: | In-line |
| Ignition system | |
| Type: | CDI/MDI or Digital Spark Advance Ignition (DSAI) ignition systems |
| Spark plug: | Champion RC12YC |
| Spark plug gap: | 0.76 mm (0.030 in) |
| Ignition coil air gap | 0.280-0.330 mm (0.011-0.013 in) |
References
1. Kohler Command PRO CH940-CH1000 service manual. Kohler Co. 2022.
Author:
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