The Kohler LH685 is a 674 cc, (41.1 cu·in) V-twin liquid-cooled four-stroke internal combustion gasoline engine from the Aegis series, manufactured by Kohler Co.
The Kohler LH685 engine has an OHV (overhead valve) design, horizontal PTO-shaft, pressurized lubrication system with oil pump. This engine is equipped with a one-barrel carburetor (Keihin) with a fixed main jet and electronic ignition system.
It has an 80.0 mm (3.15 in) cylinder bore and 67.0 mm (2.64 in) piston stroke. The compression ratio rating is 8.5:1. This engine produced 25.3 PS (18.6 KW; 25.0 HP) at 3,600 rpm of horsepower and 54.3 Nm (5.54 kg·m; 40.07 ft·lb) at 2,200 rpm of peak torque.
The breakdown of the engine code is as follows:
- L – Liquid-cooled
- H – Horizontal PTO shaft
- 685 – Numerical designation
General information
Engine Specifications | |
Model | AEGIS LH685 |
Type | 4-stroke, OHV, V-twin |
Displacement | 674 cm 3 (41.1 cu-in) |
Max. horsepower | 25.3 PS (18.6 KW; 25.0 HP) at 3,600 rpm |
Max. torque | 54.3 Nm (5.54 kg·m; 40.07 ft·lb) at 2,200 rpm |
Fuel system | One-barrel carburetor with a fixed main jet (Keihin) |
Cooling system | Liquid-cooled |
Ignition system | Electronic ignition system |
Lubricating system | Pressurized lubrication |
Starting system | Electric starter |
Fuel used | Unleaded gasoline (octane number 86 or higher) |
Cylinder Block and Head
Cylinder block | ||
Compression ratio: | 8.5:1 | |
Bore x Stroke | 80.0 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 type A | ||
Piston skirt outer diameter | 79.963-79.981 mm (3.1481-3.1488 in) | |
Connecting rod small end ID | 17.006-17.013 mm (0.6695-0.6698 in) | |
Piston pin outer diameter | 16.995-17.000 mm (0.6691-0.6693 in) | |
Side clearance: | Top | 0.050-0.096 mm (0.0020-0.0038 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 | 0.180-0.430 mm (0.0071-0.0169 in) |
Second | 0.250-0.460 mm (0.0098-0.0181 in) | |
Piston type B | ||
Piston skirt outer diameter | 79.966 mm (3.1483 in) | |
Connecting rod small end ID | 17.006-17.013 mm (0.6695-0.6698 in) | |
Piston pin outer diameter | 16.995-17.000 mm (0.6691-0.6693 in) | |
Side clearance: | Top | 0.030-0.070 mm (0.0010-0.0026 in) |
Second | 0.030-0.070 mm (0.0010-0.0026 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 bolt | Step 1: 16.9 Nm (1.72 kg·m; 12.47 ft·lb) Step 2: 33.9 Nm (3.46 kg·m; 25.02 ft·lb) |
Flywheel | 66.4 Nm (6.77 kg·m; 49.0 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: 1.6 liters (1.7 US.qts, 1.4 Imp. qts) With oil filter: 1.8 liters (1.9 US.qts, 1.58 Imp. qts) |
Cooling system | |
Type | Pressurized cooling system with integrated belt-driven water pump |
Coolant capacity | 2.0 liters (2.1 US.qts, 1.8 Imp. qts) |
Ignition system | |
Spark plug | Champion RC14YC |
Spark plug gap | 0.76 mm (0.030 in) |
Ignition module air gap | 0.2-0.3 mm (0.008-0.012 in) |
We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.
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