The Kohler CH742 is a 747 cc (45.6 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 83.0 mm (3.27 in) cylinder bore and 69.0 mm (2.72 in) piston stroke give the CH742 engine a total of 747 cc of displacement. The compression ratio rating is 9.1:1.
The CH742 engine produces 25.3 PS (18.6 KW; 25.0 HP) at 3,600 rpm of maximum horsepower and 55.9 Nm (5.7 kg·m; 41.2 ft·lb) at 2,600 rpm of peak torque.
The Kohler CH742 features:
- OHV design
- Hydraulic valve lifters
- Aluminum cylinder block
- Cast iron cylinder liners
- Hardened crank journals
- PTO side-load sleeve bearing
- CDI or MDI ignition system
- Two-barrel side-draft carburetor with fixed main jets (Walbro)
- Mechanical centrifugal governor
- Full pressure lubrication system
- Forced air cooling system
- Electric starter
General information
| Engine Specifications | |
| Engine model | Command PRO CH742 |
| Engine type | 4-stroke, OHV, V-twin |
| Displacement | 747 cm3, (45.6 cu·in) |
| Max. horsepower | 25.3 PS (18.6 KW; 25.0 HP) at 3,600 rpm |
| Max. torque | 55.9 Nm (5.7 kg·m; 41.2 ft·lb) at 2,600 rpm |
| Cooling system | Forced air |
| Air cleaner | High-efficiency, heavy-duty air filters |
| Lubricating system | Full pressure |
| Ignition system | Fixed timing CDI or MDI ignition system |
| Fuel system | Two-barrel side-draft carburetor with fixed main jets (Walbro) |
| 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) | 371 x 451 x 622 mm (14.6 x 17.7 x 24.5 in) |
| Dry weight | 48.0 kg (105.0 lbs) |
Cylinder Block and Head
| Cylinder block | |
| Compression ratio: | 9.1:1 |
| Cylinder bore: | 83.0 mm (3.27 in) |
| Piston stroke: | 69.0 mm (2.72 in) |
| Cylinder internal diameter (standard): | 82.988-83.013 mm (3.2672-3.2682 in) |
| Number of piston rings (compression / oil): | 2/1 |
| Piston pin diameter: | 16.995-17.000 mm (0.6691-0.6693 in) |
| Thrust face outer diameter (standard): | 82.978 mm (3.2668 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): | 0.189-0.277 mm (0.0074-0.0109 in) |
| Ring end gap (Second): | 1.519-1.797 mm (0.0598-0.0708 in) |
| Crankshaft | |
| Number of main bearings: | 2 |
| Crankshaft main journal diameter: | 40.913-40.935 mm (1.6107-1.6116 in) |
| Crankpin journal diameter: | 35.955-35.973 mm (1.4155-1.4163 in) |
| Cylinder head | |
| Valve arrangement: | OHV, gear driven |
| Valves: | 2 (4 valves in total) |
| Valve head diameter (INTAKE): | 33.370-33.630 mm (1.3138-1.324 in) |
| Valve head diameter (EXHAUST): | 29.370-29.630 mm (1.1563-1.1665 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) |
| Valve lift minimal (INTAKE): | 8.07 mm (0.3177 in) |
| Valve lift minimal (EXHAUST): | 8.07 mm (0.3177 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: 7.4 Nm (0.75 kg·m; 5.5 ft·lb) Step 2: 9.9 Nm (1.00 kg·m; 7.3 ft·lb) |
| Connecting rod cap fastener | 13.6 Nm (1.4 kgf·m; 10.0 lb·ft) |
| Cylinder head | Nut (torque in 2 increments): Step 1: 16.9 Nm (1.72 kg·m; 12.5 ft·lb) Step 2: 35.5 Nm (3.62 kg·m; 26.2 ft·lb) Bolt (torque in 2 increments) Step 1: 22.6 Nm (2.31 kg·m; 16.7 ft·lb) Step 2: 41.8 Nm (4.26 kg·m; 30.8 ft·lb) |
| Fan | 9.9 Nm (1.0 kg·m; 7.3 ft·lb) |
| Flywheel | 66.4 Nm (6.77 kg·m; 49.0 ft·lb) |
| Governor lever nut | 6.8 Nm (0.69 kg·m; 5.02 ft·lb) |
| 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 |
| Oil system | |
| Lubrication system: | Full pressure |
| Oil type: | API SG, SH, SJ, or higher |
| Recommended oil: | SAE 10W-30 |
| Oil capacity: | W/o oil filter: 1.7 L (1.8 US. qt, 1.5 Imp. qt.) With oil filter: 1.9 L (2.0 US.qts, 1.7 Imp. qts) |
| Fuel system | |
| Type: | Two-barrel side-draft carburetor with fixed main jets (Walbro) |
| Fuel pump: | Pulse type |
| Fuel filter: | In-line |
| Ignition system | |
| Type: | Fixed timing CDI or MDI ignition system |
| 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 CH682, CH732, CH742, CH752 service manual. Kohler Co. 2021.
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