Gruppo termico POLINI

Overview

The Polini 70 Evolution Cylinder Kit is the most advanced tuning kit for MBK Booster and Yamaha Minarelli Vertical engines. Completely redesigned, it brings a new level of performance to this engine type. Thanks to exclusive engineering solutions never seen before on similar engines, it delivers maximum power, efficiency, and reliability.

Technical Innovations

The cylinder has been developed using advanced fluid-dynamic design to maximize airflow efficiency and torque delivery across the entire rev range.

• Integrated reed valve housing with two dedicated ducts feeding directly into the transfer ports – an exclusive solution that improves torque and throttle response at low RPM.
• Four-petal reed valve (instead of the conventional two-petal design) supplied in the kit for faster and more efficient air/fuel mixture flow.
• Dedicated flow guide to channel air between the manifold and the reed valve, reducing turbulence and loss of pressure.
• 360° rotatable intake manifold, compatible with Polini CP carburetors (17–24 mm), offering full installation flexibility – suitable for both OEM and open air filters.
• Racing head with copper gasket, dual-ring piston, and base gaskets of 0.2 mm and 0.3 mm to fine-tune the squish clearance.

Available Versions

• 166.0074/E – with 10 mm piston pin
• 166.0074/12E – with 12 mm piston pin

Performance

In its basic setup, the Polini 70 Evolution Cylinder Kit delivers around 14 real horsepower with a strong and consistent torque curve across the rev range – a major improvement compared to traditional 70 cc cast-iron cylinders.

Recommended Components for Maximum Performance

• Polini CP carburetor (19–24 mm)
• Polini For Race or Scooter Team exhaust system
• High-speed transmission

Part numbers: 166.0074/E  |  166.0074/12E

APRILIA: AMICO 50 - SR 50 2T mod.1993
ITALJET: BAZOOKA 1 50 - PISTA 50 1/2, YANKEE, SCOOP 2/3
MBK: BOOSTER 50 - BOOSTER 50 dal 2004 -> - BOOSTER 50 NEXT GENERATION - BOOSTER 50 R, ROCKET - BOOSTER 50 SPIRIT - BOOSTER 50 TRACK - STUNT 50
YAMAHA: BW'S 50 dal 2004-> - BW'S 50 NEXT GENERATION - BW'S 50 ZUMA - SLIDER 50 - SPY 50