Description
The ProX Piston Kit for Yamaha 701 0.25 is a quarter millimeter oversize piston assembly for engines needing a modest overbore to correct minor cylinder wear or damage. This size is a common first step in the rebuild process, allowing the cylinder to be trued while leaving room for future oversizes. ProX manufactures this kit to closely mirror OEM characteristics, making it a natural choice for 701 based skis.
- 0.25 mm oversize piston kit for Yamaha 701 engines that require a light overbore.
- Kit supplies oversize piston, ring pack, wrist pin, and circlips for a complete top end set.
- Produced from a low expansion, low friction alloy and CNC machined for precise fit and consistent quality.
- Designed to operate at recommended clearances when the cylinder is bored and honed to the 0.25 mm oversize.
- Ideal for skis used in recreation, freeride, or mild performance roles where stock like manners are preferred.
With this small oversize step, builders can remove light scoring and taper while preserving as much cylinder material as possible. The ProX piston and ring combination is intended to deliver renewed compression, smooth running, and reduced exhaust haze when paired with correct machining and assembly practices. A properly rebuilt 701 can feel much more lively and dependable after installation.
Work with an experienced machine shop for the overbore, verify bore measurements and ring gaps, and inspect bottom end components thoroughly. Replace worn seals and gaskets, clean all mating surfaces, and follow manufacturer instructions for torque and assembly. With a careful break in period, the ProX 0.25 mm oversize piston kit can provide many additional seasons of reliable Yamaha 701 performance.
