40mm 50cc Cylinder Head Piston Ring Gasket Top End Rebuild Kit Compatible with Yamaha PW 50 Y-Zinger PW50 1981-2023 QT50 1979-1987 YT60 Tri-Zinger 1984-1985 YF60 4-Zinger 1986

Replaces Part Numbers: 4J2-11311-00-00 4J2-11111-00-00 BP4-HS000-00-00 517-11181-01-00 3PT-11351-00-00 95380-06600-00 90116-06269-00 3L5-11630-00-00 93310-210M0-00 4J2-11311-01-00 4J2-11111-01-00 Compatible With 1981-2023 Yamaha PW50 1979-1987 Yamaha QT50 1984-1985 Yamaha YT60 Tri-Zinger 1986 Yamaha YF60 4-Zinger

• 50cc Big Bore Rebuild Kit for Yamaha Mini Bikes‌ – Features a precision-machined 40.00mm bore and 39.20mm stroke for exact 50cc displacement, delivering restored performance and reliability for vintage and modern PW50, QT50, YT60, and YF60 models.
• ‌Direct OEM Part Replacement‌ – Fully compatible with original equipment numbers: Cylinder (4J2-11311-00-00), Cylinder Head (4J2-11111-01-00), Piston (18U-11636-00-00), Piston Ring (260-11610-24-00), Gasket (517-11181-01-00 / 3PT-11351-00-00), and Spark Plug (94701-00159-00).
• ‌Complete Top-End Assembly Package‌ – Includes: 1x Cylinder, 1x Cylinder Head, 1x Piston Kit, 1x Piston Ring Set, 1x Gasket Kit, 1x Bearing, 1x Spark Plug, 4x Cylinder Studs, and 4x Stud Nuts — everything needed for a full, no-gap rebuild.
• ‌Designed for 1979–2023 Yamaha Models‌ – Seamlessly fits: Yamaha PW50 (1981–2023), QT50 (1979–1987), YT60 Tri-Zinger (1984–1985), and YF60 4-Zinger (1986) — ideal for restoration, racing, or daily ride upgrades.
• Ready-to-Install with Protective Gloves Included‌ – Comes with 2 pairs of disposable mechanic gloves to guarantee a clean, debris-free installation.