The Wossner 8133D100 piston kit features a 69mm bore (68.94mm actual) and is designed for Yamaha YZ250 models from 1983 to 1987. Manufactured in Germany, this forged piston offers excellent strength and optimised heat dissipation, thanks to its elliptical shape that promotes uniform load distribution and prevents piston collapse during thermal expansion.

Features

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  Forged piston design for enhanced durability and strength

  
  


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  Elliptical profile for balanced load distribution under heat expansion

  
  


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  Optimised heat transfer from combustion chamber to cylinder walls

  
  


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  Engineered for two-stroke engines

  
  


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  Manufactured in Germany

  
  

Specifications

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  Bore size: 69mm (actual: 68.94mm)

  
  


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  Display displacement: 246 cm³

  
  


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  Stroke: 68.00 mm

  
  


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  Piston-to-wall clearance: 0.06 mm

  
  


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  Compression height: 36.00 mm

  
  


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  Compression ratio (Wossner & OEM): 2-stroke

  
  

Cross-Reference OEM Part Numbers

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  Piston Kit: 8133D100

  
  


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  Lock: CW18

  
  


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  Pin: WP033

  
  


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  Ring Set: RSB6900 x 2

  
  


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  Rod: P2048 (for 1983–1989 models)

  
  

Vehicle Fitments

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  Yamaha YZ250 (1983–1987)