| Engine Specifications | |
| Model | GX160 T1 |
| Type | 4-stroke, OHV, single cylinder inclined by 25° |
| Displacement | 163 cm 3 (9.9 cu-in) |
| Max. horsepower | 5.5 HP (4.4 kW) at 4,000 rpm |
| Max. torque (crank PTO) | 11 N·m (1.1 kg·m, 8 ft·lb) at 2,500 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/PSh |
| PTO shaft rotation | Counterclockwise (from PTO shaft side) |
| Cylinder block | ||
| Compression ratio: | 7.5:1 or 8.5:1 | |
| Bore x Stroke | 68 X 45 mm (2.7 x 1.8 in) | |
| Sleeve internal diameter | 68.00 mm (2.68 in) | |
| Piston skirt outer diameter | 67.985 mm (2.6766 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Ring side clearance | Top | 0.015-0.045 mm (0.0006-0.0018 in) |
| Second/Oil | 0.015-0.045 mm (0.0006-0.0018 in) | |
| Ring end gap | Top/Second | 0.20-0.40 mm (0.008-0.016 in) |
| Oil | 0.15-0.35 mm (0.006-0.014 in) | |
| Ring width | Top/Second | 1.5 mm (0.06 in) |
| Oil | 2.5 mm (0.10 in) | |
| Connecting rod small end ID | 18.005 mm (0.7087 in) | |
| Connecting rod big end ID | 30.02 mm (1.182 in) | |
| Piston pin outer diameter | 18.000 mm (0.71 in) | |
| Crankshaft crank pin outer diameter | 29.98 mm (1.180 in) | |
| Cylinder Head | ||
| Warpage (limit) | 0.10 mm (0.004 in) | |
| Valve Arrangement: | OHV | |
| Valves: | 2 | |
| Stem outer diameter (standard): | INTAKE | 5.48 mm (0.216 in) |
| EXHAUST | 5.44 mm (0.214 in) | |
| Valve spring free length: | 30.5 mm (1.20 in) | |
| Camshaft outer diameter: | 13.984 mm (0.5506 in) | |
| Cam height: | INTAKE | 27.7 mm (1.09 in) |
| EXHAUST | 27.75 mm (1.093 in) | |
| Tightening torque specs | |
| Connecting rod bolt | 12 Nm; 1.2 kg·m; 9 ft·lb |
| Cylinder head bolt | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Flywheel nut | 75 Nm; 7.5 kg·m; 54 ft·lb |
| Rocker arm pivot lock nut | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Rocker arm pivot bolt | 24 Nm; 2.4 kg·m; 17 ft·lb |
| Crankcase cover bolt | 12 Nm; 1.2 kg·m; 9 ft·lb |
| Oil level switch joint nut | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Oil drain bolt | 18 Nm; 1.8 kg·m; 13 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 |
| Engine | |
| Maximum speed | 3,900 ± 100 rpm |
| Idle speed | 1,400 ± 150 rpm |
| Cylinder compression | 6.0-8.5 kg/cm2 (85-121 psi) at 600 rpm |
| Valve clearance | |
| Intake valve clearance | 0.15±0.02 mm (0.006±0.001 in) |
| Exhaust valve clearance | 0.20±0.02 mm (0.008±0.001 in) |
| Oil system | |
| Oil type | Honda 4-stroke or an equivalent (SE or SF) |
| Recommended oil | SAE 10W-30 |
| Oil capacity | 0.6 L (0.63 US. qt, 0.53 Imp. qt.) |
| Carburetor | |
| Main jet |
Externally vented carburetor bowl: #72 Internally vented carburetor bowl: #68 |
| Float height | 13.7 mm (0.54 in) |
| Pilot screw opening |
Externally vented carburetor bowl: 2 turns out Internally vented carburetor bowl: 2-1/8 turns out |
| Ignition system | |
| Ignition timing | 25° 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) |
| Primary ignition coil resistance | 0.8-1.0 Ω |
| 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 | 11.0 mm (0.43 in) |
| Mica depth | 1.6 mm (0.06 in) |