The Zongshen GB680 is a 679 cc, (41.4 cu·in) natural aspirated V-twin cylinders four-stroke air-cooled internal combustion small gasoline engine with a horizontal shaft, manufactured by Zongshen Power Co for general-purpose applications.
The Zongshen GB680 engine has V-twin cylinders, an overhead valve (OHV) design, and a recoil or electric starter. This engine used a carburetor fuel system, transistorized magneto ignition system, splash type lubricating system, and forced-air cooling system.
The GB680 engine produced 19.7 PS (14.5 kW; 19.4 HP) at 3,600 rpm of maximum horsepower and 42 N·m (4.3 kg·m, 31 ft·lb) at rpm of maximum torque.
|Engine type||4-stroke, OHV, two-cylinders|
|Displacement||679 cm3, (41.44 cu·in)|
|Max. horsepower||19.7 PS (14.5 kW; 19.4 HP) at 3,600 rpm|
|Max. torque||42 N·m (4.3 kg·m, 31 ft·lb) at rpm|
|Cooling system||Forced air|
|Lubricating system||Splash type|
|Ignition system||Transistorized ignition|
|Fuel consumption||370 g/kWh|
|Fuel used||Unleaded gasoline (octane number 86 or higher)|
|Starting system||Recoil / electric starter|
|PTO shaft rotation||Counterclockwise (from PTO shaft side)|
|Dimensions (L x W X H)||462 x 428 x 456 mm (18.2 x 16.9 x 18 in)|
|Dry weight||46.5 kg (102.5 lbs)|
Cylinder Block and Head
A 78.0 mm (3.07 in) cylinder bore and 71.0 mm (2.8 in) piston stroke give the GB680 engine a total of 679 cc of displacement. The compression ratio rating is 8.5:1.
|Cylinder bore:||78.0 mm (3.07 in)|
|Piston stroke:||71.0 mm (2.8 in)|
|Number of piston rings (compression / oil):||2/1|
|Crankshaft center distance:||35.5 mm (1.4 in)|
The 4-stroke engine oil with a viscosity of SAE 10W-30 is recommended for the GB680, refilling oil capacity is 1.2 L (1.27 US. qt, 1.06 Imp. qt.). The valve clearance is 0.10-0.15 mm (0.0039-0.0059 in) for intake valves and 0.15-0.20 mm (0.006-0.008 in) for exhaust valves.
|Maximum speed:||3,900 rpm|
|Idle speed:||1,450±150 rpm|
|Intake valve clearance (COLD):||0.10-0.15 mm (0.0039-0.0059 in)|
|Exhaust valve clearance (COLD):||0.15-0.20 mm (0.0059-0.0079 in)|
|Oil type:||4-stroke engine oil|
|Recommended oil:||SAE 10W-30|
|Oil capacity:||1.2 L (1.27 US. qt, 1.06 Imp. qt.)|
|Spark plug gap:||0.6-0.8 mm (0.0236-0.0315 in)|
|Spark plug torque:||20 N·m (2 kg·m, 14.7 ft·lb)|