| Engine Specifications | |
| Model | GX270 |
| Type | 4-stroke, OHV, single cylinder, inclined by 25° |
| Displacement | 270 cm 3 (16.5 cu-in) |
| Max. horsepower | 9.12 PS (9.0 HP, 6.7 kW) at 3600 rpm |
| Max. torque (crank PTO) | 19.5 Nm (1.95 kg·m, 14 ft·lb) |
| Carburetor | Horizontal type, butterfly valve |
| Cooling system | Forced-air |
| Ignition system | Transistorized magneto ignition |
| Lubricating system | Splash |
| Starting system | Recoil or electric starter |
| Stoping system | Ignition primary circuit ground |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Fuel tank capacity | 6.0 L (1.59 US gal, 1.32 lmp gal) |
| Fuel consumption | 313 g/kWh (230 g/HPh, 0.51 lb/HPh) |
| PTO shaft rotation | Counterclockwise (from PTO shaft side) |
| Type S | Type Q | Type L | Type R | Type H | Type W | Type P | Type V | |
| Length, mm (in) | 355 (14.0) | 380 (15.0) | 405 (15.9) | 440 (17.3) | 425 (16.7) | 370 (14.6) | 380 (15.0) | 400 (15.7) |
| Width, mm (in) | 430 (16.9) | |||||||
| Height, mm (in) | 410 (16.1) | |||||||
| Dry weight, kg (lb) | 25 (55.1) | 25 (55.1) | 26.5 (58.4) | 30 (66.1) | 26.5 (58.4) | 25 (55.1) | 25 (55.1) | 25 (55.1) |
| Operating weight, kg (lb) |
30 (66.1) | 30 (66.1) | 31.5 (69.4) | 35 (77.2) | 31.5 (69.4) | 30 (66.1) | 30 (66.1) | 30 (66.1) |
| Cylinder block | ||
| Compression ratio: | 8.2 | |
| Bore x Stroke | 77 X 58 mm (3.0 x 2.3 in) | |
| Sleeve internal diameter | 77.00 mm (3.031 in) | |
| Piston skirt outer diameter | 76.985 mm (3.0309 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Ring side clearance | Top/second/oil | 0.015-0.045 mm (0.0006-0.0018 in) |
| Ring end gap | Top/second | 0.2-0.4 mm (0.01-0.02 in) |
| Oil | 0.2-0.7 m (0.01-0.03 in) | |
| Ring width | Top/second | 2.0 mm (0.08 in) |
| Crankshaft outer diameter | 32.985 mm (1.2986 in) | |
| Cylinder Head | ||
| Warpage (limit) | 0.10 mm (0.004 in) | |
| Valve Arrangement: | Overhead valve | |
| Valves: | 2 | |
| Stem outer diameter (standard): | INTAKE | 6.59 mm (0.259 in) |
| EXHAUST | 6.55 mm (0.258 in) | |
| Cam height: | INTAKE | 31.52-31.92 mm (1.241-1.257 in) |
| EXHAUST | 31.56-31.96 mm (1.243-1.258 in) | |
| Camshaft outer diameter: | 15.984 mm (0.6293 in) | |
| Engine | |
| Maximum speed | 3850 ± 150 rpm |
| Idle speed | 1400 ± 150 rpm |
| Cylinder compression | 6.0-8.5 kg/cm2 (85-151 psi) at 600 rpm |
| Valve clearance | |
| Intake valve | 0.15 ± 0.02 (0.006 ± 0.001) |
| Exhaust valve | 0.20 ± 0.02 (0.008 ± 0.001) |
| Carburetor | |
| Main jet | Externally vented carburetor bowl: #88 Internally vented carburetor bowl: #95 |
| Float height | 13.2 mm (0.52 in) |
| Pilot screw opening | 2 |
| Oil system | |
| Oil type | Honda 4-stroke or an equivalent (SG.SF/CC.CD) |
| Recommended oil | SAE 10W-30 |
| Oil capacity | 1.1 L (1.16 US gal, 0.97 lmp qt) |
| Ignition system | |
| Ignition timing | 20 ° B.T.D.C (Fixed) |
| Spark plug |
NGK: BP6ES, BPR6ES NIPPONDENSO: W20EP-U, W20EPR-U |
| Spark plug gap | 0.7-0.8 mm (0.028-0.031 in) |
| Spark plug cap | 7.5-12.5 kΩ |
| Primary ignition coil resistance | 0.8-1.0 kΩ |
| Secondary ignition coil resistance | 5.9-7.1 kΩ |
| Ignition coil air gap | 0.4 ± 0.2 (0.016 ± 0.008) |
| Starter motor | |
| Brush length | 7.2 mm (0.28 in) limit: 3.5 mm (0.14 in) |
| Mica depth | 1.0 mm (0.04 in) limit: 0.2 mm (0.01 in) |
| Tightening torque specifications | |
| Connecting rod bolt (M8x1.25 Special) | 14 Nm; 1.4 kg·m; 10 ft·lb |
| Cylinder head bolt (M10x1.25) | 35 Nm; 3.5 kg·m; 25 ft·lb |
| Flywheel nut (M16x1.5 Special) | 115 Nm; 11.5 kg·m; 83 ft·lb |
| Rocker arm pivot lock nut (M6x0.5) | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Rocker arm pivot bolt (M8x1.25 Special) | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Crankcase cover bolt (M8x1.25) | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Oil level switch joint nut (M10x1.25) | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Fuel filter joint nut (M10x1.25) | 2 Nm; 0.2 kg·m; 1.4 ft·lb |
| Muffler mounting nut (M8x1.25) | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Air cleaner wing nut (M6x1.0) | 9 Nm; 0.9 kg·m; 6.5 ft·lb |
| Oil drain bolt (M12x1.5) | 23 Nm; 2.3 kg·m; 17 ft·lb |
| Fuel tank bolt (M8x1.25) | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Air cleaner mounting nut (M6x1.0) | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Fuel strainer cup (M24x1.0) | 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 |
| Bolt, nut (6 mm) | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Bolt, nut (8 mm) | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Bolt, nut (10 mm) | 37.5 Nm; 3.75 kg·m; 27 ft·lb |
| Bolt, nut (12 mm) | 55 Nm; 5.5 kg·m; 40 ft·lb |
