Part No. 56-W4649.WI (oro2u.com)
YAMAHA YZ400F YZF400 1998-1999,
YAMAHA WR400F WRF400 1998-2000,
Overview of Wiseco Piston Assembly - 92mm Bore - 4649M09200 Forged from high silicon aluminum alloy for maximum strength and dependability

Wiseco offers a complete range of popular piston models and years for both trail and racing applications WISECO PRICING All Wiseco Hi Performance Motorcycle Pistons are priced with rings and circlips
WISECO FEATURES PRO-LITE PISTONS•Durability, longevity and increased horsepower Innovative forging design and piston skirt provide maximum

horsepower and torque