The Honda GX140 is a 144 cc (8.8 cu-in) single-cylinder, air-cooled, four-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 (8.8 cu-in) of displacement. The compression rato rating is 8.7:1. This engine produces 5.0 PS (3.6 KW; 4.8 HP) at 4,000 rpm and 9.8 Nm (1.0 kg·m; 7.23 lbf·ft) at 2,800 rpm of torque.
General information
| Engine Specifications | |
| Model | GX140 |
| Type | 4-stroke, OHV, single cylinder, inclined by 25° |
| Displacement | 144 cm 3 (8.78 cu-in) |
| Max. horsepower | 5.0 PS (3.6 KW; 4.8 HP) at 4,000 rpm |
| Max. torque (crank PTO) | 9.8 Nm (1.0 kg·m; 7.23 lbf·ft) at 2,800 rpm |
| Carburetor | Horizontal type, butterfly valve |
| Cooling system | Forced-air |
| Ignition system | Transistorized magneto ignition |
| Lubricating system | Splash |
| Starting system | Recoil starter |
| Stoping system | Ignition primary circuit ground |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Fuel tank capacity | 3.6 l (0.95 US. Gal, 0.79 Imp. Gal.) |
| Fuel consumption | 230 g/HPh |
| PTO shaft rotation | Counterclockwise (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: | 8.7:1 | |
| Bore x Stroke | 64 mm X 45 mm (2.5 x 1.77 in) | |
| Sleeve internal diameter | 64.000-64.015 mm (2.5196-2.5197 in) | |
| Piston skirt outer diameter | 63.965-63.985 mm (2.5183-2.5190 mm) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Ring side clearance (Top) | 0.015-0.045 (0.0006-0.0018) | |
| Ring side clearance (Second) | 0.015-0.045 (0.0006-0.0018) | |
| Ring end gap (Top) | 0.200-0.400 mm (0.0079-0.0157 in) | |
| Ring end gap (Second) | 0.200-0.400 mm (0.0079-0.0157 in) | |
| Ring end gap (Oil) | 0.150-0.350 mm (0.006-0.0137 in) | |
| Ring width (Top) | 1.5 mm (0.059 in) | |
| Ring width (Second) | 1.5 mm (0.059 in) | |
| Ring width (Oil) | 2.5 mm (0.98 in) | |
| Piston pin outer diameter: | 17.994-18.000 mm (0.7084-0.7087in) | |
| Crankshaft main journal diameter: | 30.000 mm (1.1811 in) | |
| Cylinder Head | ||
| Warpage (limit) | 0.10 mm (0.004 in) | |
| Valve Arrangement: | OHV | |
| Valves: | 2 | |
| Stem outer diameter (INTAKE): | 5.468-5.480 mm (0.2152-0.2157 in) | |
| Stem outer diameter (EXHAUST): | 5.425-5.440 mm (0.2135-0.2141 in) | |
| Cam height (INTAKE): | 27.70 mm (1.0905 in) | |
| Cam height (EXHAUST): | 27.75 mm (1.0925 in) | |
| Camshaft journal diameter: | 14.00 mm (0.5511 in) | |
Service Information
| Engine | |
| Maximum speed | 4,000 ± 150 rpm |
| Idle speed | 1,400 ± 150 rpm |
| Cylinder compression | 6.0-8.5 kg/cm2 (85-151 psi) at 600 rpm |
| Carburetor | |
| Type | Horizontal type, butterfly valve |
| Main jet | #68 |
| Float height | 13.7±1.5 mm (0.54±0.06 in) |
| Pilot screw opening | 1 turns out |
| Oil system | |
| Oil type | Honda 4-stroke or an equivalent (SE or SF) |
| Recommended oil | SAE 10W-30 |
| Oil capacity | 0.6 P (0.63 US. qt, 0.53 Imp. qt.) |
| Ignition system | |
| Spark plug | NGK: BPR6ES NIPPONDENSO: W20EPR-U |
| Ignition timing | B.T.D.C. 25° / 1,400 rpm |
| Spark plug gap | 0.7-0.8 mm (0.028-0.031 in) |
| Ignition coil air gap | 0.2-0.6 mm (0.01-0.02 in) |
Engine applications
- Pressure washers
- Commercial lawn and garden equipment
- Tillers / cultivators
- Generators
- Construction / industrial equipment
- Agricultural equipment
- Small vehicles
- Water pumps
Author:
what is the engine output shaft size of the handa GX140 5 Hp Honda motor
Do you mean the length of the shaft or the width? as I could go check
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?
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.
Bonjour,
Quelle est la pression d’éjection svp?
@Kenny Millar – The output shaft diameter should be 3/4 inch. I believe the GX140 engine is still available. If you are on a tight budget, you might consider the Lifan LF160F-AQ. It is a Chinese Honda clone (a “Chonda”) and is rated 4hp, not 5hp, but it should bolt right up. Lifan engines are probably the best Chonda engines available. I know both Home Depot and Amazon sell them.