Wiseco PK1394 GP Series Top End Kit 54mm 2-Stroke Piston Kit

The Wiseco PK1394 is a complete GP Series top end kit designed for the 2004 Honda CR125R, featuring a standard 54mm bore (841M05400) forged piston built to outperform OEM components in both endurance and sustained-RPM 2-stroke applications. This kit represents Wiseco's premium GP Series line, which builds upon the proven Pro-Lite foundation with advanced coating technologies for superior durability and power output.

GP Series Performance Features:

• Electra-Coated crown, ring groove, and pin bore — resists wear, combustion heat damage, and ring micro-welding for extended service intervals
• ArmorGlide skirt coating — reduces piston-to-cylinder friction to maximize power delivery and reduce heat buildup
• Dedicated aerospace-alloy forging — engineered specifically for this application with an optimized strength-to-weight ratio
• CNC diamond-turned finish — precision machining ensures consistent bore sizing with no dimensional variation
• Compatible with cast iron, chrome, Nikasil, and boron composite cylinder bore compositions
• Engineered, forged, and machined in the USA (Mentor, OH)

Kit Includes:

• Wiseco GP Series forged piston (841M05400) — 54.00mm standard bore
• High-performance piston ring (2126CS)
• Alloy wrist pin
• Circlips
• Wiseco top end gasket kit
• Premium top end needle bearing

The PK1394 is the ideal top end rebuild solution for 2004 Honda CR125R riders seeking race-proven reliability. Wiseco GP Series pistons are trusted by top race teams across all disciplines of motorsport and are engineered to meet or exceed OEM sealing and durability standards.