Honda GX22

Honda GX22 engineThe Honda GX22 is a 22 cc single-cylinder air-cooled four-stroke internal combustion ultra-small gasoline engine manufactured by Honda Motor Company since 1997. In 2002 the GX22 engine were replaced with the Honda GX25.

Honda developed the compact, lightweight, and 360°-inclinable 4-stroke GX22 engine, in the aim of producing a 4-stroke engine as easy to use as a 2-stroke. The GX22 engine is a suitable power source for handheld applications like brush-cutters and non-handheld applications like concrete screeds, tillers, and pumps.

This engine has an OHV design with valve rocker arms and camshaft driven by a maintenance-free, low-noise timing belt, makes the engine more compact and light.

It has a recoil starter, diaphragm type carburetor, transistorized magneto ignition. Bore is 33.0 mm (1.3 in) and stroke is 26.0 mm (1.0 in). The Honda GX22 ultra-small motor produced 1.014 PS (1.0 HP, 0.74 kW) at 7000 rpm and 1.09 Nm (0.11 kg·m, 0.80 ft·lb) at 6500 rpm.

General information

Engine Specifications
Type4-stroke, OHV, single cylinder
Displacement22 cm 3 (1.3 cu-in)
Max. horsepower1.014 PS (1.0 HP, 0.74 kW) at 7000 rpm
Max. torque1.09 Nm (0.11 kg·m, 0.80 ft·lb) at 6500 rpm
CarburetorDiaphragm type
Cooling systemForced-air
Ignition systemTransistorized magneto ignition
Lubricating systemPumping spray
Starting systemRecoil starter
Stoping systemIgnition primary circuit ground
Fuel usedUnleaded gasoline (octane number 86 or higher)
Fuel tank capacity0.45 L (0.12 US gal, 0.10 lmp gal)
Fuel consumption340 g/kWh (250 g/HPh, 0.55 lb/HPh)
PTO shaft rotationCounterclockwise (from PTO shaft side)

Dimensions and Weight

Length, mm (in)210 (8.3)
Width, mm (in)251 (9.9)
Height, mm (in)249 (9.8)
Dry weight, kg (lb)3.3 (7.3)

Cylinder Block and Head

Cylinder block
Compression ratio:8.0:1
Bore x Stroke33 X 26 mm (1.3 x 1.0 in)
Sleeve internal diameter33.00 mm (1.299 in)
Piston skirt outer diameter32.99 mm (1.298 in)
Ring end gapTop/second0.10-0.25 mm (0.004-0.010 in)
Ring widthTop/second0.98 mm (0.039 in)
Oil0.015-0.050 mm (0.006-0.0020 in)
Cylinder Head
Warpage (max)0.2 mm (0.01 in)
Valve Arrangement:OHV
Stem outer diameter (standard):INTAKE3.985 mm (0.1569 in)
EXHAUST3.950 mm (0.1555 in)
Valve guide outer diameter4.000 mm (0.1575 in)
Cam height:INTAKE22.79 mm (0.897 in)
EXHAUST22.79 mm (0.897 in)
Camshaft outer diameter:5.020 mm (0.1976 in)

Maintenance data

Idle speed3100 ± 200 rpm
Cylinder compression2.9-5.9 kg/cm2 (0.3-0.6 MPa, 41-84 psi) at 1200 rpm
Valve clearance
Intake valve0.12 ± 0.02 (0.005 ± 0.001)
Exhaust valve0.15 ± 0.02 (0.006 ± 0.001)
Main jet#36
Oil system
Oil typeHonda 4-stroke or an equivalent (SG, SF)
Recommended oilSAE 10W-30
Oil capacity0.1 L (0.1 US gal, 0.1 lmp qt)
Ignition system
Ignition timing27 ° B.T.D.C (Fixed)
Spark plugNGK: C5HSB, CR5HSB
Spark plug gap0.6-0.7 mm (0.024-0.028 in)
Primary ignition coil resistance0.7-0.9 kΩ
Secondary ignition coil resistance3.6-5.5 kΩ
Ignition coil air gap0.35-0.5 mm (0.014-0.020 in)

Tightening torque specs

Tightening torque specs
Flywheel nut (M8)15 Nm; 1.5 kg·m; 11 ft·lb
Crankcase bolt (M5 5×55 mm)7 Nm; 0.75 kg·m; 5.1 ft·lb
Crankcase bolt (M5 5×18 mm)5 Nm; 0.55 kg·m; 3.6 ft·lb
Camshaft cover bolt (M4)3 Nm; 0.35 kg·m; 2.2 ft·lb
Recoil starter pulley (M8)8 Nm; 0.8 kg·m; 5.8 ft·lb
Clutch bolt (M6)10 Nm; 0.1 kg·m; 7 ft·lb
Cylinder head cover bolt (M5)4 Nm; 0.4 kg·m; 2.9 ft·lb
Standard torque values
Bolt, nut (5 mm)5.5 Nm; 0.55 kg·m; 4.0 ft·lb
Screw (3 mm)1 Nm; 0.1 kg·m; 0.7 ft·lb
Screw (6 mm)9 Nm; 0.9 kg·m; 6.5 ft·lb
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.


  1. I see you don’t monetize, don’t waste your traffic, you can earn additional
    bucks every month with new monetization method. This is the best adsense alternative for any type
    of website (they approve all websites), for more info simply search in gooogle: murgrabia’s

Leave a Reply

Your email address will not be published.