Derbi Variant intake kit 28mm carburetor Metrakit

If you notice that your Derbi Variant lacks that final push or the engine falls short when you demand more, the issue is usually with the intake. The stock system greatly limits the air and fuel flow, preventing high-displacement cylinders from breathing as they should to deliver their full power.

With this Metrakit intake kit, we install a reed valve spacer made from high-strength 7075 aluminium. Its ultra-short structure positions the reeds very close to the crankcase, which drastically improves pre-compression and the intake angle of the mixture. This results in a much more aggressive crankcase filling, making the bike rev up with immediate force from low RPM. In addition, its precision machining allows you to keep the original engine mounting shaft without complications.

The heart of the kit is the Metrakit V4X reed valve, developed by Moto Tassinari. By using a double prism system with 4 carbon petals, the opening surface is twice that of a conventional reed valve. This allows the engine to rev higher at high RPM and gives instant throttle response, as carbon reacts much faster than standard metal or fibre reeds. The machined aluminium intake manifold together with its rubber connector ensure that the MRDII 28mm carburettor sits at the exact angle, avoiding turbulence and ensuring a constant flow to the cylinder.

Technical specifications

• Spacer material: CNC machined 7075 aluminium
• Reed valve: V4X by Moto Tassinari (4 petals)
• Reed material: Carbon
• Connector diameter: 35 millimetres
• Carburettor compatibility: MRDII 24mm and 28mm
• Engine compatibility: Start, Start 3 and Start 5 crankcases

The kit includes

• Reed valve spacer in 7075 aluminium
• Metrakit V4X reed valve
• Intake manifold in machined aluminium
• Rubber connector specific for MRDII carburettors
• MRDII 28mm carburettor
• High-pressure gasket set
• Steel bolts

Compatible models

DERBI

• VARIANT START
• VARIANT START 3
• VARIANT START 5