The Honda GX22 is a 22 cc (1.3 cu-in) single-cylinder, air-cooled, four-stroke cycle, 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 1.01 PS (1.0 HP, 0.74 kW) at 7,000 rpm and 1.09 Nm (0.11 kg·m; 0.8 lbf·ft) at 6,500 rpm.
General information
Engine Specifications | |
Model | GX22 |
Type | 4-stroke, OHV, single-cylinder |
Displacement | 22 cm 3 (1.3 cu-in) |
Max. horsepower | 1.01 PS (1.0 HP, 0.74 kW) at 7,000 rpm |
Max. torque | 1.09 Nm (0.11 kg·m; 0.8 lbf·ft) at 6,500 rpm |
Carburetor | Diaphragm type |
Cooling system | Forced-air |
Ignition system | Transistorized magneto ignition |
Lubricating system | Pumping spray |
Starting system | Recoil starter |
Stoping system | Ignition primary circuit ground |
Fuel used | Unleaded gasoline (octane number 86 or higher) |
Fuel tank capacity | 0.45 liters (0.48 US.qts, 0.4 Imp. qts) |
Fuel consumption | 340 g/kWh (250 g/HPh, 0.55 lb/HPh) |
PTO shaft rotation | Counterclockwise (from PTO shaft side) |
Dimensions and Weight
SC | SE | |
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 Stroke | 33.0 X 26.0 mm (1.3 x 1.0 in) | |
Sleeve internal diameter | 33.00 mm (1.299 in) | |
Piston skirt outer diameter | 32.99 mm (1.298 in) | |
Piston ring end gap (Top): | 0.10-0.25 mm (0.004-0.010 in) | |
Piston ring end gap (Second): | 0.10-0.25 mm (0.004-0.010 in) | |
Ring width (Top): | 0.98 mm (0.039 in) | |
Ring width (Second): | 0.98 mm (0.039 in) | |
Ring width (Oil): | 0.015-0.050 mm (0.006-0.0020 in) | |
Cylinder Head | ||
Warpage (max) | 0.2 mm (0.01 in) | |
Valve Arrangement: | OHV | |
Valves: | 2 | |
Valve stem outer diameter (INTAKE): | 3.985 mm (0.1569 in) | |
Valve stem outer diameter (EXHAUST): | 3.950 mm (0.1555 in) | |
Valve guide outer diameter | 4.000 mm (0.1575 in) | |
Camshaft cam height (INTAKE): | 22.79 mm (0.897 in) | |
Camshaft cam height (EXHAUST): | 22.79 mm (0.897 in) | |
Camshaft outer diameter: | 5.020 mm (0.1976 in) |
Maintenance data
Engine | |
Idle speed | 3,100 ± 200 rpm |
Cylinder compression | 2.9-5.9 kg/cm2 (0.3-0.6 MPa, 41-84 psi) at 1,200 rpm |
Valve clearance | |
Intake valve | 0.12 ± 0.02 (0.005 ± 0.001) |
Exhaust valve | 0.15 ± 0.02 (0.006 ± 0.001) |
Carburetor | |
Main jet | #36 |
Oil system | |
Oil type | Honda 4-stroke or an equivalent (SG, SF) |
Recommended oil | SAE 10W-30 |
Oil capacity | 0.10 liters (0.11 US.qts, 0.10 Imp. qts) |
Ignition system | |
Ignition timing | 27 ° B.T.D.C (Fixed) |
Spark plug | NGK: C5HSB, CR5HSB DENSO: U16FS-UB, U16FSR-UB |
Spark plug gap | 0.6-0.7 mm (0.024-0.028 in) |
Primary ignition coil resistance | 0.7-0.9 Ω |
Secondary ignition coil resistance | 3.6-5.5 kΩ |
Ignition coil air gap | 0.35-0.50 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 |
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.
Thank you for specs on the gx.
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