72cc steel cylinder kit 6 volts

Complete 72cc cylinder kit for 6-volt motorbike ( Honda ST50-70 – SS50 – CD50 – CF50-70 )

Kit consisting of :

• steel cylinder 72cc with 49cc marking
• piston with piston rings
• piston pin
• 2 x circlip

W STANDARD Cylinder & Piston Set

Product description

This complete set consists of an air-cooled cylinder and piston for engine blocks. The cylinder is marked as 49cc, whilst the oversized bore ensures a actual cylinder capacity of 72cc.

Suitable for modifying and upgrading various small horizontal engine blocks.

The complete set consists of a cylinder, piston, piston rings, piston pin and retaining rings and is ready for fitting.

Specifications

Cylinder mounting dimensions

• Total length of upper flange: 48.5 mm
• Flange width: 50.5 mm
• Width of lower mounting point: 46.5 mm
• Internal distance of the lower flange: 52.5 mm
• Centre-to-centre distance: 47 mm
• Total height of the cylinder cooling block: 88.5 mm
• Height of cooling fins: 62.6 mm

Piston

• Total piston height: 47.8 mm
• Height of piston skirt: 47 mm
• Distance from the top of the piston spring groove to the bottom of the piston: 24.2 mm
• Length of the section with piston spring grooves: 20.1 mm
• Compression piston rings: 2 pieces – groove width 1.2 mm
• Oil-seal spring: 1 piece – groove width 2.5 mm

Piston pin & retaining rings

• Piston pin: Ø 13 mm – length 38 mm
• Circlips: outer diameter 14.9 mm – thickness 1.0 mm

Features

✅ Air-cooled cylinder with reinforced cooling fins for efficient heat dissipation.
✅ Precisely fitted piston with matching piston rings to ensure a good seal.
✅ Complete set including all the parts required for assembly.
✅ Upgrade from a standard model 49cc to 72cc, for a noticeable increase in power.
✅ Ideal for mini motorbikes, pit bikes and other small horizontal engine blocks.

Manufacturer : W/standard

English Product Description
Product Name: W STANDARD Cylinder & Piston Kit (Marked 49cc barrel, actual displacement 72cc)
Product Overview
This complete kit comprises an air-cooled motorcycle engine cylinder barrel and piston assembly. The cylinder barrel is marked as a 49cc specification, whilst the overbore design delivers an actual displacement of 72cc. It is suitable for modifying and upgrading a range of small horizontal engines.
The complete set includes the cylinder barrel, piston, piston rings, piston pin and circlips, ready for immediate fitting.
Specifications
Cylinder Barrel Mount Dimensions
Overall length of top flange: 48.5 mm
Flange width: 50.5 mm
Bottom mounting width: 46.5 mm; inner flange distance: 52.5 mm; centre distance: 47 mm
Total height of the cylinder cooling body: 88.5 mm; fin height: 62.6 mm
Piston Parameters
Total piston height: 47.8 mm
Piston skirt height: 47 mm
Distance from the top of the ring groove to the piston crown: 24.2 mm; length of the ring groove section: 20.1 mm
Compression ring grooves: 2, groove width 1.2 mm
Oil ring groove: 1 piece, groove width 2.5 mm
Piston Pin & Circlips
Piston pin: Ø13 mm, length 38 mm
Circlip: outer diameter 14.9 mm, thickness 1.0 mm
Features
✅ Integrated cooling cylinder with reinforced cooling fins, ensuring stable heat dissipation during air-cooled operation
✅ High-precision piston paired with standard piston rings for excellent airtightness
✅ Complete accessory set; no additional separate parts required
✅ Upgrade directly from the standard 49cc engine to a 72cc displacement for a noticeable power boost. The ideal modification part for mini motorbikes and pit bikes.