{"product_id":"namura-na-40010-2k-top-end-kit-100-47-mm-0-020-in-11-1-compression-for-yamaha-grizzly-660-and-rhino-660","title":"Namura NA-40010-2K Top End Kit, 100.47 mm +0.020 in, 11:1 Compression for Yamaha Grizzly 660 and Rhino 660","description":"\u003cp\u003eThe Namura NA-40010-2K Top End Kit is designed for rebuilding the upper end of select Yamaha 660cc engines. This 100.47 mm +0.020 in oversize kit features an 11:1 compression ratio and includes the piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit needed for a comprehensive installation. It is engineered for dependable fitment and performance in compatible Yamaha ATV and side-by-side applications.\u003c\/p\u003e\u003cp\u003eThe piston uses a hypereutectic casting process that increases silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. Its MOS2, or Teflon\/Molybdenum, coated skirts are applied using a rolled-on process that creates a durable bond while helping transfer heat, reduce friction, 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.\u003c\/p\u003e\u003cp\u003eThis Namura top-end rebuild kit fits 2002–2008 Yamaha YFM660FG Grizzly 4WD IRS models and 2004–2006 Yamaha YXR660F Rhino 660 models, provided the engine has been prepared for the specified oversize piston. Confirm cylinder condition, bore requirements, compression specifications, and year-specific application details before installation. The manufacturer part number and vendor part number are both NA-40010-2K.\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\u003eOversize Piston: 100.47 mm, or +0.020 inch, piston size with an 11:1 compression ratio for compatible rebuilt engines.\u003c\/li\u003e\n\u003cli\u003eMOS2-Coated Skirts: Rolled-on Teflon\/Molybdenum coating helps create a strong bond while reducing friction, improving heat transfer, and helping prevent cold seizures.\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 in demanding operating conditions.\u003c\/li\u003e\n\u003cli\u003eHypereutectic Construction: Higher silicon content helps reduce expansion, improve wear resistance, and tolerate increased cylinder temperatures.\u003c\/li\u003e\n\u003cli\u003eFitment: Fits 2002–2008 Yamaha YFM660FG Grizzly 4WD IRS models and 2004–2006 Yamaha YXR660F Rhino 660 models.\u003c\/li\u003e\n\u003cli\u003eBrand and Part Number: Namura NA-40010-2K; manufacturer and vendor part number NA-40010-2K.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2002 Yamaha YFM660FG Grizzly 4WD [IRS]\u003cbr\u003e\n2003 Yamaha YFM660FG Grizzly 4WD [IRS]\u003cbr\u003e\n2004 Yamaha YFM660FG Grizzly 4WD [IRS]\u003cbr\u003e\n2004 Yamaha YXR660F Rhino 660\u003cbr\u003e\n2005 Yamaha YFM660FG Grizzly 4WD [IRS]\u003cbr\u003e\n2005 Yamaha YXR660F Rhino 660\u003cbr\u003e\n2006 Yamaha YFM660FG Grizzly 4WD [IRS]\u003cbr\u003e\n2006 Yamaha YXR660F Rhino 660\u003cbr\u003e\n2007 Yamaha YFM660FG Grizzly 4WD [IRS]\u003cbr\u003e\n2007 Yamaha YXR660F Rhino 660\u003cbr\u003e\n2008 Yamaha YFM660FG Grizzly 4WD [IRS]","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67559041007851,"sku":"186-40102","price":198.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/dd77-572a583cd9540_8257bdd3-4899-4884-8e15-db2829757ad3.jpg?v=1790769706","url":"https:\/\/ctracingservices.com\/products\/namura-na-40010-2k-top-end-kit-100-47-mm-0-020-in-11-1-compression-for-yamaha-grizzly-660-and-rhino-660","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}