Description
This ProX Piston Kit for Kawasaki STX 15F 2004 2014 and Ultra LX 2007 2014 in the B size range is designed for cylinders that fall into a specific bore class within the factory tolerance band. Many OEM style engines use A, B, or C graded pistons to fine tune fit, and this B variant follows that approach while maintaining ProX’s focus on high quality construction. It is ideal for builders wanting an OEM like approach to matching piston size to cylinder measurements.
- B size piston kit suited for properly measured STX 15F and Ultra LX cylinders requiring this bore classification.
- Kit contents include piston, ring set, wrist pin, and circlips, giving you everything you need for the piston group.
- Made from a low expansion, low friction alloy and CNC machined for consistent dimensions and smooth operation.
- Works within manufacturer style clearance ranges when the cylinder is checked and matched to the B size specification.
- Fits the same Kawasaki four stroke models outlined for the broader 01.4554 series of pistons.
Choosing the correct A, B, or C size piston helps optimize noise, longevity, and ring sealing in precision four stroke engines. When paired with a properly honed and measured cylinder, this ProX B piston can offer quiet operation, stable compression, and an OEM like feel on the water. It is a practical option for owners who value refined running characteristics as much as simple durability.
Accurate measurement is essential, so use proper bore gauges and follow Kawasaki and ProX recommendations for matching cylinder size to piston class. Take the opportunity to service valves, stem seals, and timing components while the engine is open. With careful attention to detail, this ProX B size piston kit can contribute to a rebuild that feels tight, smooth, and ready for many seasons of use.
