Description
The ProX Piston Kit for Yamaha GPR800/1200 A size is a stock bore replacement piston intended for cylinders that gauge in the tighter end of the factory tolerance band. Many Yamaha performance engines are graded A, B, or C from the factory, and using the correct size group helps control noise, wear, and ring sealing. This kit keeps the lively, responsive feel of GPR engines while refreshing critical top end parts.
- A size standard bore piston kit for Yamaha GPR800 and GPR1200 models that measure in the small side of OEM spec.
- Supplied with piston, ring set, wrist pin, and circlips, giving builders a matched assembly for one cylinder.
- Low expansion, low friction alloy is chosen to mimic OEM thermal characteristics in high output two stroke use.
- Precision CNC machining supports accurate skirt profile, dome shape, and ring groove geometry.
- Ideal for riders who want OEM style manners and reliability with renewed compression and response.
When paired with a light hone and good bore finish, this A size ProX piston can deliver clean idle, snappy throttle, and strong pull through the rev range. The ring package is designed to seat quickly and hold compression over many hours of hard use on lakes, rivers, or surf. It is a sensible choice for both stock and mildly modified GPR builds.
Engine builders should carefully measure cylinder diameters with the correct tools to confirm A sizing, then verify ring gaps and piston to wall clearances. Replace gaskets and seals, check crankshaft and bearings, and be sure cooling systems are functioning properly. With proper assembly and break in, the ProX A size GPR800/1200 piston kit can keep these popular Yamaha machines running hard for seasons to come.
