{"product_id":"namura-na-40004k-standard-bore-top-end-kit-for-2001-2005-yamaha-yfm660r-raptor","title":"Namura NA-40004K Standard Bore Top End Kit for 2001–2005 Yamaha YFM660R Raptor","description":"\u003cp\u003eThe Namura NA-40004K Standard Bore Top End Kit is a complete replacement solution for the top end of select Yamaha YFM660R Raptor engines from 2001 through 2005. Designed for dependable fitment and reliable performance, this kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit. It is engineered to restore compression and support consistent engine operation during demanding off-road riding.\u003c\/p\u003e\u003cp\u003eThe piston features MOS2, or Teflon\/Molybdenum, coated skirts applied through a rolled-on process for a durable bond. This coating helps reduce friction, improve heat transfer, and minimize the risk of cold seizures. Machined smooth heads help reflect combustion heat and reduce carbon buildup, while the anodized dome improves heat resistance and durability. The hypereutectic casting process adds silicon for reduced expansion, increased wear resistance, and improved performance under elevated cylinder temperatures.\u003c\/p\u003e\u003cp\u003eDesigned as a standard-bore replacement, the Namura NA-40004K top end kit supports the original engine configuration when properly installed with compatible components. Verify engine condition, bore specifications, and service requirements before installation. This kit fits 2001, 2002, 2003, 2004, and 2005 Yamaha YFM660R Raptor models.\u003c\/p\u003e\u003cp\u003e\u003cb\u003eFeatures:\u003c\/b\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eComplete Top End Kit: Includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit\u003c\/li\u003e\n\u003cli\u003eStandard Bore Piston: Designed for replacement applications using the original standard cylinder bore\u003c\/li\u003e\n\u003cli\u003eMOS2-Coated Skirts: Teflon\/Molybdenum coating helps reduce friction, improve heat transfer, and minimize cold-seizure risk\u003c\/li\u003e\n\u003cli\u003eMachined Smooth Head: Helps reflect combustion heat and reduce carbon buildup on the piston crown\u003c\/li\u003e\n\u003cli\u003eAnodized Dome: Improves heat resistance and piston durability under demanding operating conditions\u003c\/li\u003e\n\u003cli\u003eHypereutectic Casting: Higher silicon content supports reduced expansion and increased wear resistance\u003c\/li\u003e\n\u003cli\u003eFitment: Fits 2001–2005 Yamaha YFM660R Raptor models\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2001 Yamaha YFM660R Raptor\u003cbr\u003e\n2002 Yamaha YFM660R Raptor\u003cbr\u003e\n2003 Yamaha YFM660R Raptor\u003cbr\u003e\n2004 Yamaha YFM660R Raptor\u003cbr\u003e\n2005 Yamaha YFM660R Raptor","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67559051690219,"sku":"186-4004","price":187.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/2d37-5e99b63a091ba.jpg?v=1790770020","url":"https:\/\/ctracingservices.com\/products\/namura-na-40004k-standard-bore-top-end-kit-for-2001-2005-yamaha-yfm660r-raptor","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}