Kohler K181

Kohler K181The Kohler K181 is a 305 cc (18.6 cu·in) single-cylinder air-cooled four-stroke internal combustion gasoline engine from K-series, manufactured by Kohler Co.

The Kohler K181 engine has an L-head (side valve) design and horizontal PTO-shaft. This engine can be equipped with Kohler or Walbro carburetor and magneto, battery or breakerless ignition systems. The K181 engine used paper air cleaner (oiled foam pre-cleaner was available as an option).

The cylinder bore is 74.62 mm (2.94 in) and the piston stroke is 69.85 mm (2.75 in). This engine produced 8.2 PS (6.0 kW; 8.0 HP) at 3,600 rpm of horsepower.

The breakdown of the engine code is as follows:

  • K – K-series
  • 18 – Approximate daisplacement (cu·in)
  • 1 – Single cylinder
  • Suffix (engine is available with the following options):
    S – Electric starter;
    T – Retractable starter;
    ST – Electric and retractable starter;
    EP – Electric plant;
    A – Special oil pan;
    C – Clutch model;
    G – Generator applications;
    P – Pump model;
    Q – Quled model;
    R – Reduction gear;

General information

Engine Specifications
Model K181
Type 4-stroke, L-head, single cylinder
Displacement 308 cm 3 (18.6 cu-in)
Max. horsepower 8.2 PS (6.0 kW; 8.0 HP) at 3,600 rpm
Max. torque (crank PTO)
Fuel system Carburetor (Kohler or Walbro, fixed main jet or adjustable main jet)
Cooling system Forced-air
Ignition system Magneto or battery or breakerless ignition system
Lubricating system Splash type
Starting system Recoil or electric starter
Fuel used Unleaded gasoline (octane number 86 or higher)
Fuel tank capacity

Cylinder Block and Head

Cylinder block
Compression ratio:
Bore x Stroke 74.62 X 69.85 mm (2.94 x 2.75 in)
Sleeve internal diameter 74.6252-74.5998 mm (2.938-2.937 in)
Piston skirt outer diameter 74.4143-74.3737 mm (2.9297-2.9281 in)
Number of piston rings (compression / oil): 2 / 1
Ring end gap Top 0.177-0.432 mm (0.007-0.017 in)
Second 0.177-0.432 mm (0.007-0.017 in)
Connecting rod small end ID 15.8877-15.8953 mm (0.6255-0.6258 in)
Piston pin outer diameter 15.8673-15.8724 mm (0.6247-0.6249 in)
Cylinder Head
Valve Arrangement: L-head (sidevalve)
Valves: 2
Valve head diameter: INTAKE 34.925 mm (1.375 in)
EXHAUST 28.575 mm (1.125 in)
Stem outer diameter (standard): INTAKE 7.886-7.899 mm (0.3105-0.311 in)
EXHAUST 7.848-7.861 mm (0.309-0.3095 in)

Tightening torque specs

Tightening torque specs
Cylinder head bolt 20-27 Nm; 2.0-2.7 kg·m; 15-20 ft·lb
Flywheel 115-122 Nm; 11.7-12.3 kg·m; 85-90 ft·lb
Spark plug 25-30 Nm; 2.55-3.06 kg·m; 18-22 ft·lb

Service Information

Engine
Max speed 3,600 rpm
Valve clearance
Intake valve clearance 0.15-0.20 mm (0.0059-0.0079 in)
Exhaust valve clearance 0.43-0.48 mm (0.0169-0.0189 in)
Oil system
Oil type API SF or SG
Recommended oil Summer: SAE 30W
Winter: SAE 5W-20, 5W-30
Oil capacity 1.2 L (1.27 US. qt, 1.06 Imp. qt.)
Ignition system
Spark plug Champion: RJ8C
Spark plug gap 0.65 mm (0.0256 in)
ATTENTION! Dear visitors, this site is not a trading platform, an official dealer or a spare parts supplier, so we do not have any price lists or spare parts catalogs. We are an information portal and provide the technical specifications of gasoline and diesel engines.

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.

5 Comments

  1. JUST GOT AN OLD KEE MSGC-25 S.P.WITH A 8HP KOHLER K181T SPEC NO.30667.HAS A NEWER LOOKING WHITE STICKER WITH A BAR CODE AND SERIAL NO 15012082 ON IT.WOUNDERING ABOUT THAT,INFO? BUT THIS INFO HAS BEEN VERY HELPFULL,THANKS

  2. Does the K181 have a 1″ output shaft ? This is what I need for the 2 belt pulley to drive the Binks air compressor.

  3. Does the K181 have a 1″ output shaft ? This is what I need for the 2 belt pulley to drive the Binks air compressor.
    The flywheel cracked in 2 places,so is there a replacement one ?

  4. Looking for specks on oem fule psi..I’m done with cheep China pumps….that being said I’m gonna go electric pump…and I don’t wanna over work the float….please email answer….thank you.

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