The 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) |
Author:
Helpful information. Good service to us who don’t know everything.
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
Does the K181 have a 1″ output shaft ? This is what I need for the 2 belt pulley to drive the Binks air compressor.
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 ?
the k181s does it turn clockwise or cou ter clockwise
I’m rebuilding an antique K181S, needed the torque specs and very happy to have found them here but nothing on the piston cap. Oh well, I’ll keep searching, thank you.