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 |
Thank you for specs on the gx.
Thanks for the accurate information