Honda GX670 Technical Specifications

Engine Specifications
Model GX670
Type 4-stroke, OHV, 90° V-twin
Displacement 670 cm 3 (40.9 cu-in)
Max. horsepower 24 HP (17.7 kW HP) at 3,600 rpm
Max. torque (crank PTO) 50.8 N·m (5.18 kg·m, 37.5 ft·lb) at 2,500 rpm
Carburetor Horizontal type, butterfly valve
Cooling system Forced-air
Ignition system Transistorized magneto ignition
Lubricating system Forced lubrication
Starting system Electric starter
Stoping system Ignition primary circuit ground
Fuel used Unleaded gasoline (octane number 86 or higher)
Fuel consumption 265 g/HPh
PTO shaft rotation Counterclockwise (from PTO shaft side)
Cylinder block
Compression ratio: 8.3:1
Bore x Stroke 77 X 72 mm (3.0 x 2.8 in)
Sleeve internal diameter 77.00 mm (3.03 in)
Piston skirt outer diameter 76.985 mm (3.03 in)
Cylinder Head
Warpage (limit) 0.10 mm (0.004 in)
Valve Arrangement: OHV
Valves: 4 (2 per cylinder)
Tightening torque specs
Connecting rod bolt 12 Nm; 1.2 kg·m; 9 ft·lb
Cylinder head bolt 34 Nm; 3.5 kg·m; 25 ft·lb
Socket bolt 27 Nm; 2.7 kg·m; 20 ft·lb
Flywheel nut 196 Nm; 20.0 kg·m; 145 ft·lb
Pivot bolt 24 Nm; 2.4 kg·m; 17 ft·lb
Pivot adjusting nut 10 Nm; 1.0 kg·m; 7 ft·lb
Cylinder head cover bolt 9 Nm; 0.9 kg·m; 6.5 ft·lb
Oil level switch joint nut 10 Nm; 1.0 kg·m; 7 ft·lb
Oil drain bolt 39 Nm; 4.0 kg·m; 29 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) 22 Nm; 2.2 kg·m; 16 ft·lb
Bolt, nut (10 mm) 34 Nm; 3.5 kg·m; 25 ft·lb
Bolt, nut (12 mm) 54 Nm; 5.5 kg·m; 40 ft·lb
Engine
Maximum speed 3,850 ± 100 rpm
Idle speed 1,400 ± 150 rpm
Cylinder compression 6.0-8.0 kg/cm2 (85-114 psi) at 500 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 (SG or SF)
Recommended oil SAE 10W-30
Oil capacity 1.90 L
Oil change interval Every 6 month or 100 Hrs.
Ignition system
Spark plug NGK: ZGR5A
DENSO: J16CR-U
Spark plug gap 0.7-0.8 mm (0.028-0.031 in)