Honda GX140

Honda GX140 engineThe Honda GX140 is a 0.14 l (144 cc) single-cylinder air-cooled 4-stroke internal combustion small gasoline engine manufactured by Honda Motor Company since 1983 for general-purpose applications.

This engine has a single cylinder inclined by 25° overhead valve design for increased efficiency and optimal power transfer, sophisticated air intake system, large capacity, multi-chamber exhaust system, heavy-duty recoil starter.

A 64.0 mm (2.5 in) cylinder bore and 45.0 mm (1.77 in) piston stroke give the engine a total of 144 cc of displacement. It produces 3.6 kW (5.0 PS) at 4,000 rpm and 9.8 N·m (1.0 kg·m, 7.7 ft·lb) of torque at 2,800 rpm.

General information

Engine Specifications
Type4-stroke, OHV, single cylinder, inclined by 25°
Displacement144 cm 3 (8.78 cu-in)
Max. horsepower5.0 PS (3.6 kW) at 4000 rpm
Max. torque (crank PTO)9.8 N·m (1.0 kg·m, 7.7 ft·lb) at 2800 rpm
CarburetorHorizontal type, butterfly valve
Cooling systemForced-air
Ignition systemTransistorized magneto ignition
Lubricating systemSplash
Starting systemRecoil starter
Stoping systemIgnition primary circuit ground
Fuel usedUnleaded gasoline (octane number 86 or higher)
Fuel tank capacity3.6 l (0.95 US. Gal, 0.79 Imp. Gal.)
Fuel consumption230 g/HPh
PTO shaft rotationCounterclockwise (from PTO shaft side)

Dimensions and Weight

GX140 “S-Type”
Length, mm (in)315 (12.4)
Width, mm (in)355 (14.4)
Height, mm (in)335 (13.2)
Dry weight, kg (lb)14.0 (30.9)

Cylinder Block and Head

The Honda GX140 has cast iron cylinder sleeve, ball bearing supported crankshaft, improved piston design, heavy-duty balancer shaft.

Cylinder block
Compression ratio:8.7
Bore x Stroke64 mm X 45 mm (2.5 x 1.77 in)
Sleeve internal diameter64.00 mm (2.5196 in)
Piston skirt outer diameter63.985 mm (2.5190 in)
Number of piston rings (compression / oil):2 / 1
Cylinder Head
Warpage (limit)0.10 mm (0.004 in)
Valve Arrangement:OHV

Service Information

Maximum speed4000 ± 150 rpm
Idle speed1400 ± 150 rpm
Cylinder compression6.0-8.5 kg/cm2 (85-151 psi) at 600 rpm
Oil system
Oil typeHonda 4-stroke or an equivalent (SE or SF)
Recommended oilSAE 10W-30
Oil capacity0.6 P (0.63 US. qt, 0.53 Imp. qt.)
Ignition system
Spark plugNGK: BPR6ES
Spark plug gap0.7-0.8 mm (0.028-0.031 in)

Engine applications

  • Pressure washers
  • Commercial lawn and garden equipment
  • Tillers / cultivators
  • Generators
  • Construction / industrial equipment
  • Agricultural equipment
  • Small vehicles
  • Water pumps
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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.


  1. I have an older Honda GX140 5 hp with a “roughly” 3/4″ 14 tooth splined shaft. I need to couple this engine with a hydraulic pump. Any help?

  2. I have a plate compactor with this engine. The engine has no compression, and I’d like to replace it with a new equivalent. Any suggestions for a direct-swap.
    Or can anyone tell me the output shiaft diameter so I can find an equivalent motor.

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