Yamaha YZ 85 Top End Piston Kit - Vertex Pistons (`19-`23) is a direct replacement top-end kit designed to restore compression and reliability to 2019–2023 YZ85 engines. This exact-fit kit is available in A, B or C sizes and includes all parts needed for a proper rebuild.

Built by Vertex and heat treated with a T-5 hardening and tempering cycle, these pistons are engineered for consistent dimensions and durability. Skirts receive a molybdenum disulphide (MoS2) coating to promote a faster break-in and longer piston life. Each kit contains the piston, ring set, wrist pin and circlips so you have everything required to complete the top-end service. Exact fit A, B or C sizes match your cylinder bore to reduce blow-by and control oil consumption without guesswork.

Features

• Exact fit A, B or C options for 2019–2023 Yamaha YZ85
• Piston, rings, wrist pin and circlips included
• T-5 heat treatment for strength and consistency
• Skirt MoS2 coating for quicker break-in and improved wear
• Manufactured by Vertex to OEM-compatible specifications

If you have questions about fitment or installation, call us directly — we’re happy to help. We offer installation and customization services at our Austin, Texas and Los Angeles, California area locations. Call our Texas shop at 512-982-9393 or our California shop at 562-981-6800. If you’re thinking about purchasing multiple items, contact us for shipping discounts. We install on premises at both locations.

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov