Wössner products are to be found in engines operating at the highest levels of motorsport, in competition and, of course, in everyday use – in fact, anywhere, where longevity, highest performance and operational noise are important factors. Wössner products are the source of the superior power behind the success of well known motorsport teams at national and international race meets, and with distribution points and warehouses in Europe, North America and Asia our products are just a phone call away.

KIT INCLUDES

• Piston
• Piston Pin
• Circlips
• Rings 

FEATURES:

• In-house designed and manufactured; all forgings are produced in Wössner's company-owned forging operation
• Lightweight pistons with the tightest piston-wall clearances in the industry give you a quieter running engine
• Wössner pistons are used by leading Supercross, Arenacross and MX GP teams
• Made in Germany

PISTON SPECIFICATIONS

A PISTON:

• Standard Compression
• Compression Ratio: 12.5:1
• Cylinder Diameter: 92.00mm
  
• Displacement: 400cc
  
• Piston Diameter: 91.95mm

B PISTON:

• Standard Compression
• Compression Ratio: 12.5:1
• Cylinder Diameter: 92.01mm
  
• Displacement: 400cc
  
• Piston Diameter: 91.96mm

C PISTON:

• Standard Compression
• Compression Ratio: 12.5:1
• Cylinder Diameter: 92.02mm
  
• Displacement: 400cc
  
• Piston Diameter: 91.97mm

Note: Please ensure you have measured and selected the correct size piston.

Note: Image for reference only. Correct product will be provided.

BIKE FITMENT

YAMAHA

• WR400F 1998-2000
• YZ400F 1998-1999