PISTON KIT 75-81 DT400 MX 85.5, WOSSNER 8263D050 YAMAHA

This Wossner piston kit features an 85.50mm bore size (85.42mm actual) and is designed for Yamaha DT400 and MX410 models. Manufactured in Germany, this forged piston is engineered for strength and thermal efficiency. The elliptical design supports even load distribution during expansion, reducing the risk of piston collapse by preventing localised pressure points. Features include forged construction for increased strength, elliptical design for uniform load distribution under heat expansion, and promotion of efficient combustion chamber heat transfer to cylinder walls. Specifications include a bore size of 85.50mm (85.42mm), display of 398 cm³, stroke of 70.00 mm, clearance of 0.08 mm, compression height of 40.00 mm, and a 2-stroke compression ratio (Wossner and OEM). Cross-reference OEM part numbers include Piston Kit: 8263D050, Lock: CW18, Pin: WP042, Ring Set: RSC8550 x2, and Part No.: 56-W549_0.50.WO. The kit weighs 532 grams.