The Kohler CH680 is a 674 cc, (41.0 cu·in) V-twin air-cooled four-stroke internal combustion gasoline engine from the Command PRO series, manufactured by Kohler Co.
The Kohler CH680 engine has an OHV (overhead valve) design, an aluminum block with cast iron cylinder liners, a horizontal PTO-shaft, pressurized lubrication system. This engine is equipped with a carburetor (Nikki or Keihin) with a fixed main jet and one of these ignition systems: CDI/MDI, ASAM/DSAM, DSAI (Digital Spark Advance Ignition).
The cylinder bore and the piston stroke are 80.0 mm (3.15 in) and 67.0 mm (2.64 in), respectively. Compression ratio rating is 8.5:1.
The Kohler CH680 engine produced 22.8 PS (16.8 KW; 22.5 HP) at 3,600 rpm of horsepower and 49.9 Nm (5.09 kg·m; 36.83 ft·lb) at 2,400 rpm of torque.
The breakdown of the engine code is as follows:
- C – Command series
- H – Horizontal PTO shaft
- 680 – Numerical designation
General information
| Engine Specifications | |
| Model | Command PRO CH680 |
| Type | 4-stroke, OHV, V-twin |
| Displacement | 674 cm 3 (41.0 cu-in) |
| Max. horsepower |
22.8 PS (16.8 KW; 22.5 HP) at 3,600 rpm 23.4 PS (17.2 KW; 23.0 HP) at 3,600 rpm |
| Max. torque | 49.9 Nm (5.09 kg·m; 36.83 ft·lb) at 2,400 rpm |
| Fuel system | Carburetor with a fixed main jet (Nikki or Keihin) |
| Cooling system | Forced-air |
| Ignition system | CDI/MDI, ASAM/DSAM, DSAI (Digital Spark Advance Ignition) |
| Lubricating system | Pressurized lubrication |
| Starting system | Electric starter |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Dimensions (L x W X H) | 355 x 451 x 483 mm (14.0 x 17.7 x 19.0 in) |
| Dry weight | 41.0 kg (90.0 lbs) |
Cylinder Block and Head
| Cylinder block | ||
| Compression ratio: | 8.5:1 | |
| Bore x Stroke | 80.0 mm X 67.0 mm (3.15 x 2.64 in) | |
| Sleeve internal diameter | 80.000-80.025 mm (3.1496-3.1506 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Piston style A | ||
| Thrust face outer diameter | 79.943-79.961 mm (3.1473-3.1480 in) | |
| Piston pin outer diameter | 16.995-17.000 mm (0.6691-0.6693 in) | |
| Ring-to-groove side clearance: | Top | 0.030-0.076 mm (0.0012-0.0030 in) |
| Second | 0.030-0.076 mm (0.0012-0.0030 in) | |
| Oil | 0.046-0.196 mm (0.0018-0.0077 in) | |
| Ring end gap: | Top | 0.180-0.460 mm (0.0071-0.0181 in) |
| Second | 0.180-0.460 mm (0.0071-0.0181 in) | |
| Piston style B | ||
| Thrust face outer diameter | 79.966 mm (3.1483 in) | |
| Piston pin outer diameter | 16.995-17.000 mm (0.6691-0.6693 in) | |
| Ring-to-groove side clearance: | Top | 0.030-0.070 mm (0.001-0.0026 in) |
| Second | 0.030-0.070 mm (0.001-0.0026 in) | |
| Oil | 0.060-0.190 mm (0.0022-0.0073 in) | |
| Ring end gap: | Top | 0.100-0.279 mm (0.0039-0.0110 in) |
| Second | 1.400-1.679 mm (0.0551-0.0661 in) | |
| 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 drive | |
| Valves: | 4 (2 per cylinder) | |
| Valve head diameter: | INTAKE | 33.370-33.630 mm (1.3138-1.324 in) |
| EXHAUST | 29.370-29.630 mm (1.1563-1.1665 in) | |
| Stem outer diameter: | INTAKE | 6.982-7.000 mm (0.2749-0.2756 in) |
| EXHAUST | 6.970-6.988 mm (0.2744-0.2751 in) | |
Tightening torque specs
| Tightening torque specs | |
| 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) |
| Flywheel | 66.4 Nm (6.77 kg·m; 49 ft·lb) |
| Spark plug | 27 Nm (2.75 kg·m; 20.0 ft·lb) |
Service Information
| Oil system | |
| 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) |
| Ignition system | |
| Spark plug | Champion RC12YC |
| Spark plug gap | 0.76 mm (0.030 in) |
| Ignition module air gap | 0.280-0.330 mm (0.011-0.013 in) |
Will this engine (Kohler CH680 ) act as a replacement for my Walker Mower 23 HP Kohler? My current engine is burning oil and running rough.