Kit Cylinder and Crankshaft Italkit 73cc 40mm stroke Derbi Variant Start 3

Cylinder and Crankshaft Kit Italkit for Derbi Variant Start 3.

The Italkit 73cc cylinder kit with a 40 mm stroke increases engine torque and power throughout the entire rev range. This high-displacement cylinder assembly is designed to optimize the dynamic performance of the geared engine, delivering a much more immediate and forceful acceleration response.

The aluminum cylinder features a 48 mm bore and a two-ring piston with a 12 mm wrist pin. When combined with the Italkit crankshaft with the original 40 mm stroke, it provides precise balancing capable of withstanding the demands of tuning. The two-piece Cylinder Head with removable insert helps maintain an optimal temperature in the combustion chamber, reducing the risk of overheating under intensive use conditions.

To achieve the best mechanical performance, it is recommended to combine this kit with a larger-diameter carburetor and a sport-range exhaust. The corresponding gasket kit is specified to ensure the sealing of the crankcase and cylinder.

Technical specifications

• Kit reference: K.12.574.G
• Displacement: 73cc
• Cylinder bore: 48 mm
• Stroke: 40 mm (original stroke)
• Piston pin: 12 mm
• Number of rings: 2
• Cylinder Head: 2 pieces (cover and insert)
• Crankshaft: C-40 mm Ø12 mm (CB.12.5)
• Complete cylinder reference: CI.12.573.GD
• Gasket kit reference: VJ.12.11

Compatible models

DERBI

• Variant Start 3 1997-2002