Manufactured by Namura
Kit includes piston, rings, pin, clips, wrist pin bearing & top end gasket kit (you get exactly what is pictured)
Cast piston has super-high silicone content for additional strength
Piston skirts are Molybdenium Teflon coated to minimize resistance/wear and provide extended life
Piston dome is anodized for superior heat resistance and longer lifespan
Namura gaskets use performance materials to increase durability and provide greater reliability
Includes all gaskets pictured to rebuild top end
Kit is for standard bore size - 66.40mm
Size A piston is 66.35mm
Compression ratio of 10.9:1
Made in Taiwan


Namura NX-40025K


  • 1999 Yamaha YZ250
  • 2000 Yamaha YZ250
  • 2001 Yamaha YZ250

YZ250 99-01 Namura - Top End Repair Kit Standard Bore - NX- 40025K

Excluding Sales Tax