The 156 shares the same parts as the 962. The cylinder and piston are the only main differences.
Displacement: 56.5 cc closed port
Bore: 46 mm
Stroke: 34 mm
Max RPM: 13,000-13,500
Spark plug: NGK BPMR6A
Power: 4.1 HP at 9000 rpm
Fuel: 700 ml (23.67 oz)
Oil: 350 ml (11.83 oz)
Weight: 5.5 kg (12.1 lbs)