Polini 78.8cc big bore kit for Piaggio 4T 50cc showing finned aluminum alloy cylinder, flat-top piston, 3-ring piston ring set, circlips, wrist pin, dowel pins, green composite head gasket, black base gasket, exhaust gasket, and rubber intake manifold spacers Polini 78.8cc big bore kit for Piaggio 4T 50cc showing finned aluminum alloy cylinder, flat-top piston, 3-ring piston ring set, circlips, wrist pin, dowel pins, green composite head gasket, black base gasket, exhaust gasket, and rubber intake manifold spacers
Polini 78.8cc big bore kit for Piaggio 4T 50cc showing finned aluminum alloy cylinder, flat-top piston, 3-ring piston ring set, circlips, wrist pin, dowel pins, green composite head gasket, black base gasket, exhaust gasket, and rubber intake manifold spacers

Polini

Polini 78.8cc Big Bore Kit | Vespa Piaggio 4T 50cc Engines

SKU 1100-1467
$308.00
Shipping calculated at checkout.
Description

Bump your Piaggio 4T 50cc scooter to 78.8cc with the Polini Big Bore Kit. Designed for 4-stroke 2-valve and 4-valve 49cc Piaggio engines, this complete kit includes a finned aluminum alloy cylinder, flat-top piston, full gasket set, and all hardware needed for the bore-up. The 11.6:1 compression ratio delivers a significant increase in mid-range and top-end power, and the included gear-up ratio (14:43) provides a 60% increase over stock (11:54) for improved top speed.

For off-road and closed-course competition use only. Not intended for use on public roads or land. Not legal for use in California on pollution-controlled vehicles. Performance upgrades are not covered under warranty.

Kit Contents

  • Finned aluminum alloy cylinder (78.8cc bore)
  • Flat-top piston
  • Piston rings (3-ring set)
  • Circlips (x2)
  • Wrist pin and dowel pins
  • Head gasket (green composite)
  • Base gasket (black)
  • Exhaust gasket
  • Rubber intake manifold spacers

Technical Specifications

  • Displacement: 78.8cc
  • Compression Ratio: 11.6:1
  • Gear-Up Ratio: 14:43 (60% increase over stock 11:54)
  • Cylinder Material: Aluminum alloy
  • Polini Part Number: 140.0223
  • Made in Italy

Compatibility

  • Vespa LX 50 (2006–2009) — 4-stroke 2-valve
  • Vespa LX 50 (2010–2014) — 4-stroke 4-valve
  • Vespa S 50 (2009–2014) — 4-stroke 4-valve
  • Vespa Primavera 50 4V Carb (2015–2019)
  • Vespa Sprint 50 4V Carb (2015–2019)
  • Piaggio Fly 50 (4T)
  • Scootcoupe P50

California Prop 65 Warning: www.p65warnings.ca.gov
Product Diagrams
Features
  • Increases displacement from 49cc to 78.8cc on Piaggio 4T 2-valve and 4-valve engines
  • 11.6:1 compression ratio for significant mid-range and top-end power gains
  • 14:43 gear-up ratio — 60% increase over stock 11:54 for improved top speed
  • Complete kit: aluminum cylinder, piston, rings, circlips, wrist pin, full gasket set, and intake spacers
  • Made in Italy by Polini — Polini P/N 140.0223
Specifications

Displacement: 78.8cc | Compression: 11.6:1 | Gear-Up Ratio: 14:43 (stock 11:54) | Cylinder: Aluminum alloy | Polini P/N: 140.0223 | Origin: Italy
Model Fitments

Vespa LX 50 2006-2009 (2V), Vespa LX 50 2010-2014 (4V), Vespa S 50 2009-2014 (4V), Vespa Primavera 50 4V Carb 2015-2019, Vespa Sprint 50 4V Carb 2015-2019, Piaggio Fly 50 (4T), Scootcoupe P50
  • Same day shipping for orders placed before 2PM (CST) M-F
  • 30-day return period on eligible items
  • Flat-rate shipping for orders shipped to the 48 Contiguous United States.
Since 1989

Supplying parts and accessories for vintage and modern scooters since 1989 – Over Half a Million Served and Counting!

Comprehensive Resource

From wear-and-tear items like tires and oil filters to aftermarket parts from industry-leading brands.

Dealer Focused

With a committed team of dealer-focused sales reps and streamlined pricing and shipping processes, we are dedicated to supporting your business.

Innovative

Our team constantly strives to develop and source the best new products for your scooter.