This PROX 4-stroke piston kit is built for riders who want a reliable, accurate top-end refresh without guesswork. Precision CNC machining helps ensure consistent fitment, while the low-expansion, low-friction aluminum alloy supports stable performance under heat and load. Because the kit comes with the key components you need, it makes rebuilding simpler and helps get your engine back to strong, clean-running condition.
Whether you’re servicing a worn top end or doing preventive maintenance, this kit helps restore compression and performance so your bike stays responsive and dependable for the next hours on the engine.
Key features:
✅ Kit includes piston, rings, wrist pin and circlips
✅ Precision machined on state-of-the-art CNC equipment
✅ Made with low expansion, low friction alloy
Benefits of use:
🔹 Easier rebuild: key parts included in one matched kit
🔹 Consistent fit and operation thanks to precise machining
🔹 Reliable performance under demanding riding conditions due to stable alloy properties
Technical specifications (as provided):
📌 Brand: PROX
📌 Vendor part number: 01.4342.B
📌 Engine type: 4-Stroke
📌 Displacement: 250 cc
📌 Bore size: 77.00 mm (Oversize: Standard)
📌 Piston size: 76.97 mm
📌 Compression ratio: 13.5:1
📌 Piston material: Aluminum alloy
📌 Skirt coating: Non-coated
📌 Type: Standard Size B
📌 Units: Kit
Why choose this product?
⭐ Complete, rebuild-ready kit from a trusted performance parts brand
⭐ Designed for accurate fitment and dependable engine operation
⭐ A practical choice for maintenance intervals and performance restoration
