Venturi + Derbi Spacing Base Proton – Banshee 350

The Banshee 350 reed valve is a huge gain once fitted in our 50 crankcases. That's why Proton Factory released a spacing base that changes the bolt-hole spacing to a Derbi, Metrakit or Cone fitment: installation becomes far simpler.

The original venturi is 40 mm, way too big for our engines. The venturi supplied by Proton is 33.5 mm: the measured gain is over half a horsepower, recorded on the dyno.

The pack includes:

• The Proton spacing base
• The Proton 33.5 mm venturi

Benefits:

• 📈 Over half a horsepower gained on the dyno
• 🎯 33.5 mm venturi sized for 50 engines
• 🔧 Easier mounting with Derbi/Metrakit/Cone spacing
• ⚙️ Banshee 350 reed valve finally usable on a 50 crankcase

Note: base and venturi designed to take the Banshee 350 reed valve in a 50 crankcase (reed valve sold separately).