Stage6 Sport Pro MK2 70cc Cylinder Kit – Minarelli Horizontal LC 10mm (Yamaha Aerox / MBK Nitro)

The Stage6 Sport Pro MK2 is the evolution of the legendary MK1 — a cylinder kit that earned a massive following in the scooter tuning scene. With the MK2, Stage6 has pushed performance, reliability, and design to the next level.

Designed for 50cc scooters equipped with Minarelli horizontal LC engines, such as the Yamaha Aerox and MBK Nitro, this kit combines refined engineering with proven race-inspired features.

Design & Engineering

The MK2 cylinder was completely redesigned: 6 transfer ports (instead of 5) provide improved cylinder filling and more efficient gas flow. The oval exhaust port has been further optimized, and the external design takes inspiration from the pentagonal R/T series cylinders.
A one-piece cylinder head with integrated scavenging channels ensures excellent heat dissipation. The R/T-style piston, featuring a domed crown and 0.8 mm thin piston ring, boosts power while maintaining outstanding thermal stability.

Performance

The MK2 delivers 2–3 hp more than the MK1, achieving 14–17 hp when paired with the right setup. Known for its high output and durability, this cylinder kit is built to handle both daily riding and demanding performance applications.

Recommended setup for full potential :

• Reinforced crankshaft

• Minimum 19mm carburetor

• Sport or racing exhaust system

Installation & Setup

• Clean engine thoroughly before assembly and inspect all parts.

• Use a new spark plug and small end bearing.

• Adjust carburetor settings if necessary.

• Squish clearance: 0.75–0.85 mm

• Break-in period: approx. 300 km using a 1:33 oil mixture

Important :

• Original exhaust systems cannot be used with this cylinder.

• Temperature sensor (including thread) must not exceed 18 mm in length.

• Not homologated for road use in some countries.

Kit Includes :

• Aluminum cylinder (47.6 mm bore)

• Single-ring piston with 10 mm piston pin

• One-piece cylinder head

• Complete gasket set