Planning a rebuild on your Yamaha GP800, GP800R, or XLT WaveRunner? This top end kit has you covered for models from 1998 to 2005. It includes pistons, rings, pins, clips, and gaskets – everything you need for a fresh upper engine overhaul. The pistons are standard bore (STD), so they're perfect if your cylinders are still in good shape. Made by Ritco Products under Yamaha specs, part number 66E-11631-00-A0. Brand new in the box with a 90-day warranty. Whether you're fixing up an old jet ski or doing performance maintenance, this kit makes the job easier. Just add your tools and some time, and you'll have your WaveRunner running like new again. Great for DIYers or mechanics who know their way around two-stroke engines. Don't let worn pistons keep you off the water – get this kit and get back to riding!