{"product_id":"namura-na-10000-1k-90-21-mm-top-end-kit-for-honda-trx450-foreman","title":"NAMURA NA-10000-1K 90.21 mm Top End Kit for Honda TRX450 Foreman","description":"\u003cp\u003eThe NAMURA NA-10000-1K Top End Kit is designed for select Honda TRX450 Foreman ATVs and includes the components needed to service the engine’s top end. This kit includes a 90.21 mm piston, piston rings, wrist pin, retaining clips, top end bearing, and gasket kit. With an 11:1 compression ratio and a +0.25 mm oversize piston, the kit is intended for compatible applications requiring a precision replacement or cylinder bore service.\u003c\/p\u003e\u003cp\u003eThe piston uses NAMURA’s hypereutectic casting process, which increases silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. The piston skirts feature a rolled-on MOS2 coating made from Teflon and molybdenum. This coating is engineered to provide a strong bond, reduce friction, promote heat transfer, and help reduce the risk of cold seizures. Machined smooth heads help reflect combustion heat and limit carbon buildup, while anodized domes improve heat resistance and piston durability.\u003c\/p\u003e\u003cp\u003eFitment includes 1998–2004 Honda TRX450FE Foreman ES with SRA and 1998–2000 Honda TRX450FM Foreman S with SRA. Confirm the model year, trim, cylinder specification, and required oversize before installation. The manufacturer part number is NA-10000-1K, and the vendor part number is 186-10001.\u003c\/p\u003e\u003cp\u003e\u003cb\u003eFeatures:\u003c\/b\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eKit contents: Includes piston, rings, wrist pin, retaining clips, top end bearing, and gasket kit.\u003c\/li\u003e\n\u003cli\u003ePiston size: 90.21 mm piston with a +0.25 mm oversize specification and 11:1 compression ratio.\u003c\/li\u003e\n\u003cli\u003eMOS2-coated skirts: Rolled-on Teflon and molybdenum coating helps reduce friction, improve heat transfer, and help 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 durability compared with a non-anodized piston dome.\u003c\/li\u003e\n\u003cli\u003eHypereutectic construction: Higher silicon content helps control expansion, improve wear resistance, and withstand higher cylinder temperatures.\u003c\/li\u003e\n\u003cli\u003eFitment: Compatible with select 1998–2004 Honda TRX450FE Foreman ES SRA models and 1998–2000 Honda TRX450FM Foreman S SRA models.\u003c\/li\u003e\n\u003cli\u003eBrand and part numbers: NAMURA manufacturer part number NA-10000-1K; vendor part number 186-10001.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n1998 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n1998 Honda TRX450FM Foreman S [SRA]\u003cbr\u003e\n1999 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n1999 Honda TRX450FM Foreman S [SRA]\u003cbr\u003e\n2000 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n2000 Honda TRX450FM Foreman S [SRA]\u003cbr\u003e\n2001 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n2001 Honda TRX450FM Foreman S [SRA]\u003cbr\u003e\n2002 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n2002 Honda TRX450FM Foreman S [SRA]\u003cbr\u003e\n2003 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n2003 Honda TRX450FM Foreman S [SRA]\u003cbr\u003e\n2004 Honda TRX450FE Foreman ES [SRA]\u003cbr\u003e\n2004 Honda TRX450FM Foreman S [SRA]","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67559484948715,"sku":"186-10001","price":131.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/5ea9-5d76d56084c77_c31b32e3-9395-4c25-984c-45f4bcfabf36.jpg?v=1790772387","url":"https:\/\/ctracingservices.com\/products\/namura-na-10000-1k-90-21-mm-top-end-kit-for-honda-trx450-foreman","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}