PISTON 98-00 YZF/WR400F 92 HC WOSSNER PISTON KIT 8639DA
Piston kit 92mm Bore 91.95mm Wossner 8639DA(STD)
YAMAHA
WR 400 F 1998 - 1999,,, 
YZ 400 F 1998 - 1999,,,
 
 
Wossner forged pistons are superior in strength and design.
 
 
Engineered to provide the best possible path for combustion chamber heat transfer to cylinder walls.
 
 
Elliptically designed to provide a more uniform bearing surface under piston heat expansion, eliminating localized pressure and distributing thrust loads more evenly, thereby preventing piston collapse.
 
 
Made in Germany.

Part No. 56-W199+00A.WO (Off Road Only Ltd.) Wossner Piston Yamaha YZ400FPro 92 mm Bore (PN# 8639DA)
Lock P/N CW18
Pin P/N WP053
Ring Set P/N 920XSY