Kohler KS590

Kohler KS590The Kohler KS590 is a 541 cc (33.0 cu·in) natural aspirated single-cylinder four-stroke air-cooled small gasoline engine with a vertical shaft from the 5400 series, manufactured by Kohler Co for general-purpose applications.

The cylinder bore is 94.0 mm (3.70 in) and the piston stroke is 78.0 mm (3.10 in). The compression ratio rating is 8.8:1.

The Kohler KS590 engine produced 19.3 PS (14.2 KW; 19.0 HP) at 3,600 rpm of maximum output power and 41.4 Nm (4.22 kg·m; 30.55 ft·lb) at 2,600 rpm of peak torque.

The Kohler KS590 features:

  • OHV design
  • Electronic ignition system
  • One-barrel carburetor
  • Centrifugal governor
  • Pressure lubrication with full-flow filter
  • Forced air cooling system
  • Electric starter

General information

Engine Specifications
Engine modelKS590
Engine type4-stroke, OHV, single-cylinder
Displacement541 cm3, (33.0 cu·in)
Max. horsepower19.3 PS (14.2 KW; 19.0 HP) at 3,600 rpm
Max. torque41.4 Nm (4.22 kg·m; 30.55 ft·lb) at 2,600 rpm
Cooling systemForced air
Air cleanerReplaceable, paper element
Lubricating systemPressurized lubrication
Ignition systemElectronic ignition system
Fuel systemOne-barrel carburetor
Fuel usedUnleaded gasoline (octane number 86 or higher)
Starting systemElectric starter
Dimensions (L x W X H)457 x 394 x 360 mm (18 x 15.5 x 14.2 in)
Dry weight34.0 kg (75.0 lbs)

Cylinder Block and Head

Cylinder block
Compression ratio:8.8:1
Cylinder bore:94.0 mm (3.70 in)
Piston stroke:78.0 mm (3.10 in)
Cylinder internal diameter (standard):94.010-94.035 mm (3.7012-3.7022 in)
Piston skirt outer diameter (standard):93.975-93.989 mm (3.6998-3.7003 in)
Number of piston rings (compression / oil):2/1
Piston pin diameter:21.995-22.000 mm (0.8659-0.8661 in)
Ring-to-groove side clearance (Top):0.025-0.065 mm (0.0010-0.0026 in)
Ring-to-groove side clearance (Second):0.040-0.080 mm (0.0016-0.0032 in)
Ring-to-groove sing end gap (Oil):0.090-0.210 mm (0.0035-0.0083 in)
Ring end gap (Second):0.150-0.400 mm (0.0059-0.0157 in)
Ring end gap (Oil):1.000-1.250 mm (0.0394-0.0492 in)
Crankshaft main journal diameter:40.913-40.935 mm (1.6107-1.6116 in)
Crankpin journal diameter:40.982-41.000 mm (1.6135-1.6142 in)
Cylinder head
Valve arrangement:OHV
Valve head diameter (INTAKE):35.875-36.125 mm (1.412-1.422 in)
Valve head diameter (EXHAUST):32.875-33.125 mm (1.294-1.304 in)
Seat angle (INTAKE):44.5°
Seat angle (EXHAUST):44.5°
Valve face angle (INTAKE):45°
Valve face angle (EXHAUST):45°
Valve steam diameter (INTAKE):5.982-6.000 mm (0.2355-0.2362 in)
Valve steam diameter (EXHAUST):5.970-5.988 mm (0.2350-0.2357 in)
Minimal valve lift (INTAKE):9.4 mm (0.370 in)
Minimal valve lift (EXHAUST):9.4 mm (0.370 in)

Tightening torque specifications

Valve clearance
Cylinder Head Step 1: 24.4 Nm (2.5 kgf·m; 18.0 ft·lb)
Step 2: 42.7 Nm (4.4 kgf·m; 31.5 ft·lb)
Rocker Arm Pivot Stud13.5 Nm (1.4 kgf·m; 10 ft-lb)
Rocker Arm Adjustment Nut Set Screw5.5 Nm (0.6 kgf·m; 4.2 ft-lb)
Flywheel Retaining Screw115.0 (11.7 kgf·m; 84.9 ft·lb)
Connecting Rod Cap Step 1: 5.5 Nm (0.6 kgf·m; 4.1 ft·lb)
Step 2: 11.8 Nm (1.2 kgf·m; 8.7 ft·lb)
Cam Levers12.5 Nm (1.3 kgf·m; 9.2 ft·lb)
Oil Drain Plug14.0 Nm (1.4 kgf·m; 10.4 ft-lb)
Ignition Module Into new hole: 8.8 Nm (0.9 kgf·m; 6.5 ft-lb)
Into used hole: 3.4 Nm (0.3 kgf·m; 2.5 ft-lb)
Muffler Retaining Nuts27.8 Nm (2.8 kgf·m; 20.5 ft-lb)

Service Data

Valve clearance
Intake valve lash:0.101-0.152 mm (0.004-.006 in)
Exhaust valve lash:0.101-0.152 mm (0.004-.006 in)
Oil system
Lubrication system:Pressurized lubrication
Oil type:SJ or higher
Recommended oil:KOHLER PRO 10W-50 or SAE 10W-30
Oil capacity:1.4 liters (1.5 US.qts, 1.23 Imp. qts)
Fuel system
Type:One-barrel carburetor
Ignition system
Type:Electronic ignition system
Spark plug:Champion RC12YC
Spark plug gap:0.76 mm (0.0299 in)
Spark plug torque:27 N·m (2.8 kg·m, 19.9 ft·lb)
Module air gap:0.203-0.305 mm (0.008-0.012 in)


1. Kohler 5400 series KS530-KS595 service manual. Kohler Co. 2020.

Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

ATTENTION! Dear visitors, this is an informational database of technical specifications, we are not a parts supplier or a marketplace.

We try to use official documentation and verify the published data, but errors may occur. In addition, specifications of machinery and equipment may vary depending on markets and modifications. We do not recommend the use of this data for spare parts or repairs. Use official service manuals or parts catalogs for your product.

Be the first to comment

Leave a Reply

Your email address will not be published.