Malossi 70cc Big Bore Cylinder Kit: Genuine / Minarelli 2T

Malossi 70cc Cast Iron Sport Cylinder Kit – Yamaha Zuma / Minarelli Horizontal AC

Transform your stock 50cc into a torque-rich, reliable street machine with the legendary Malossi 70cc Cast Iron Sport Cylinder Kit. Designed and manufactured in Italy, this premium big-bore kit is engineered to deliver stronger acceleration, improved hill-climbing power, and a substantial increase in mid-range performance while maintaining the durability required for everyday riding.

By increasing displacement and utilizing Malossi's proven port design, this kit produces a broad, usable powerband that works exceptionally well with both stock and mildly modified sport setups. Whether you're looking for more pulling power around town or improved overall rideability, the Malossi Sport Kit remains one of the most trusted upgrades in the 2-stroke world.

⚠️ CRITICAL WRIST PIN FITMENT WARNING ⚠️

This cylinder kit includes a piston designed for a 10mm wrist pin crankshaft.

Most Genuine 50cc scooters and Yamaha Zuma "Bugeye" models (2002-2011) utilize a 10mm wrist pin from the factory. However, certain vintage European scooters, aftermarket crankshafts, and older Yamaha Zuma "Prebug" vertical-engine models (1989-2001) may utilize a 12mm wrist pin.

Please verify your crankshaft wrist pin size before ordering.

Failure to confirm wrist pin diameter may result in compatibility issues. We strongly recommend measuring the small-end bearing or verifying your crankshaft specifications prior to purchase.

Premium Italian Engineering

High-Strength Cast Iron Cylinder

Constructed from wear-resistant, thermal-stable cast iron designed to withstand the demands of daily riding while providing excellent longevity and consistent performance.

Optimized Port Design

Features Malossi's proven transfer and exhaust port architecture to improve cylinder filling, combustion efficiency, and low-to-mid-range torque production.

High-Compression Cylinder Head

Includes a dedicated die-cast aluminum cylinder head engineered to maximize combustion efficiency and optimize squish clearance.

Lightweight Dual-Ring Piston

Supplied with a premium aluminum piston featuring dual compression rings for excellent sealing, reliability, and long service life.

Fitment

Designed for horizontal, air-cooled (AC), 2-stroke Minarelli and Minarelli-clone engines equipped with a 10mm wrist pin crankshaft, including many:

• Yamaha Zuma 50 (Bugeye) 2002-2011
• Genuine Roughhouse 50
• Genuine Buddy 50
• CPI, Keeway, and other horizontal Minarelli-clone applications

Always verify wrist pin diameter before ordering, especially if your engine has been modified or equipped with an aftermarket crankshaft.

This is one of the most proven and reliable 70cc sport kits available, making it an excellent choice for riders seeking a substantial performance increase without sacrificing everyday dependability.

If you want even more power, check out our stage 2 kit!