Wiseco PK1891 Forged Piston Top-End Kit 12.5:1 CR ArmorGlide 96mm

The Wiseco PK1891 is a complete forged piston and top-end gasket kit engineered for the 2013–2014 Suzuki RMZ450. Running a 12.5:1 stock compression ratio and a 96.00mm bore, this kit is purpose-built to restore your machine to factory performance specifications while benefiting from Wiseco's industry-leading forging technology.

At the heart of this kit is a dedicated forged piston produced entirely in-house at Wiseco's Mentor, Ohio facility. Unlike cast pistons, Wiseco forgings feature a condensed, aligned grain structure that delivers superior tensile strength, impact resistance, and fatigue life—critical qualities in the high-RPM, high-heat environment of a competitive motocross engine.

The piston skirt features Wiseco's ArmorGlide® coating, a premium dry-film lubricant developed and validated through Wiseco's in-house dyno program. ArmorGlide reduces piston-to-bore friction, lowers heat generation, and allows for tighter bore clearances—resulting in a better ring seal, more consistent power delivery, and extended component life.

Kit Includes:

• Forged ArmorGlide-coated piston
• High-performance piston ring set
• Alloy wrist pin
• Circlips
• Complete top-end gasket kit

Key Specifications:

• Compression Ratio: 12.5:1 (Stock)
• Bore Size: 96.00mm
• Skirt Coating: ArmorGlide®
• Construction: Aerospace-alloy forged piston
• Manufactured in the USA

Whether you're completing a routine rebuild or refreshing a race-ready machine, the Wiseco PK1891 provides a reliable, one-stop solution with OEM-quality fitment and performance you can trust from a brand with over 75 years in motorsport.