Top Performances Racing Big Bore Cylinder-piston kitRef : TPF00181A / 1127343

TOP PERFORMANCE Racing Big Bore Cylinder Kit – Manufacturer Ref. 9912800

Designed for urban tuning on 50 cc scooters, this TOP PERFORMANCE Big Bore kit increases the displacement to 67.9 cc with a bore of 47 mm and a stroke of 39.2 mm. The cylinder is made of MINACROM cast iron (chrome-enriched alloy) and features 8 transfer ports — 6 opposing and 2 at the rear — to enhance filling. The "Racing" piston has a high silicon content and silver coating, with segmentation and sealing suitable for high RPMs.

Delivery contents:

• 1 cylinder Ø 47 mm in MINACROM cast iron
• 1 piston Ø 47 mm (silicon, silver coating)
• 1 chrome piston ring 1.5 mm
• 1 piston pin Ø 10 mm
• 2 circlips Ø 10 mm
• 1 head
• 1 cylinder base gasket 0.4 mm
• 1 oil drain bolt M8 and 1 water drain bolt M14
• 1 adapter for H2O head (gas 1/8)
• 3 clamps Ø16 x 25
• Various O-rings and drain gaskets (green Viton included)

Main features:

• Bore: 47 mm
• Stroke: 39.2 mm
• Displacement: 67.9 cc
• Indicated compression ratio: 1:14
• Piston: Racing compression
• Target use: Urban / tuning

Common compatibilities: YAMAHA AEROX R (SA421), MBK NITRO (2016), APRILIA SONIC 50 GP (2015). This kit is aimed at riders looking for an increase in displacement and a robust base for their tuning and carburetion adjustments in urban use.