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)