{"product_id":"piston-ring-kit-yamaha-yfb-yfm-250-os-0-75-1989-2009","title":"OS 0.75 Piston Ring Kit For Yamaha YFB YFM 250 Bear Tracker Timberwolf 1989 2009 ATV","description":"\u003cdiv\u003e\n\u003cp\u003ePrecisely engineered piston ring kit for 250cc ATV engines, designed to restore compression and reliable sealing in 1989–2009 Bear Tracker and Timberwolf family models. The OS 0.75 oversize helps reclaim bore wear, revive lost power, and cut oil consumption by renewing the piston ring seal. This aftermarket replacement delivers a cost-effective rebuild option that keeps trail work and field duties moving without the OEM price tag.\u003c\/p\u003e\n\u003cp\u003eBuilt to tackle common wear like ring land scuffing, blow-by, and compression loss from long hours in mud, dust, and heavy-duty use, this OS oversize kit re-establishes proper bore clearance and consistent sealing. It’s a dependable choice for riders who demand durable, repeatable performance in tough environments, whether crawling through mud or hauling gear across fields.\u003c\/p\u003e\n\u003ch3\u003eComprehensive Vehicle Fitment\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eManufacturer\u003c\/th\u003e\n\u003cth\u003eModels \/ Series\u003c\/th\u003e\n\u003cth\u003eYears \/ Details\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFB250 Bear Tracker\u003c\/td\u003e\n\u003ctd\u003e1992–2000\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFB250 Bear Tracker (4x4 variants)\u003c\/td\u003e\n\u003ctd\u003e1992–2000\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFB250F\u003c\/td\u003e\n\u003ctd\u003e1992–2000\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFB250U\u003c\/td\u003e\n\u003ctd\u003e1992–2000\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFM250 Timberwolf\u003c\/td\u003e\n\u003ctd\u003e1989–1991\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFM250 Timberwolf (late 1990s–2000s)\u003c\/td\u003e\n\u003ctd\u003e1999–2004\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFM250 Bear Tracker \/ Bruin variants\u003c\/td\u003e\n\u003ctd\u003e1999–2009\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFM250B\u003c\/td\u003e\n\u003ctd\u003e2005–2009\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYFM250X\u003c\/td\u003e\n\u003ctd\u003e1999–2004\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003c\/h3\u003e\n\u003ch3\u003eProduct Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eAttribute\u003c\/th\u003e\n\u003cth\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOEM Reference Part Numbers\u003c\/td\u003e\n\u003ctd\u003e4BD-11610-30-00\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003ePiston Ring Kit (Top Ring, Second Ring, Oil Ring)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eAftermarket Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eYamaha YFB250 Bear Tracker \/ YFM250 Timberwolf (1989–2009) engines\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eCast Iron alloy rings (monometal construction)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOversize\u003c\/td\u003e\n\u003ctd\u003eOS 0.75 mm (+0.75 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRing Count\u003c\/td\u003e\n\u003ctd\u003e3 rings (Top compression ring, Second compression ring, Oil ring)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility Note\u003c\/td\u003e\n\u003ctd\u003eDesigned for engines with bore sizes compatible with the Yamaha 250cc YFM\/YFB family; verify bore measurement prior to install\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003c\/h3\u003e\n\u003ch3\u003eOEM \u0026amp; Aftermarket Cross-Reference Information\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003cth\u003eBrand \/ Type\u003c\/th\u003e\n\u003cth\u003eCross-Reference Notes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e4BD-11610-30-00\u003c\/td\u003e\n\u003ctd\u003eYamaha OEM\u003c\/td\u003e\n\u003ctd\u003eOriginal equipment reference for YFB\/YFM 250 piston ring kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e4BD-11610-00-00\u003c\/td\u003e\n\u003ctd\u003eAftermarket Replacement\u003c\/td\u003e\n\u003ctd\u003eComparable aftermarket cross-reference to OEM-style kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e710XDS\u003c\/td\u003e\n\u003ctd\u003eWossner (Aftermarket)\u003c\/td\u003e\n\u003ctd\u003eCross-reference for ~71.0 mm bore (OS variations available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e715XDS\u003c\/td\u003e\n\u003ctd\u003eWossner (Aftermarket)\u003c\/td\u003e\n\u003ctd\u003eCross-reference for ~71.5 mm bore (OS variations available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e720XDS\u003c\/td\u003e\n\u003ctd\u003eWossner (Aftermarket)\u003c\/td\u003e\n\u003ctd\u003eCross-reference for ~72.0 mm bore (OS variations available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e725XDS\u003c\/td\u003e\n\u003ctd\u003eWossner (Aftermarket)\u003c\/td\u003e\n\u003ctd\u003eCross-reference for ~72.5 mm bore (OS variations available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e730XDS\u003c\/td\u003e\n\u003ctd\u003eWossner (Aftermarket)\u003c\/td\u003e\n\u003ctd\u003eCross-reference for ~73.0 mm bore (OS variations available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003c\/h3\u003e\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cp\u003eInside the box you’ll find the essential rings designed for Yamaha YFM\/YFB 250 engines:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cb\u003eTop Compression Ring\u003c\/b\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cb\u003eSecond Compression Ring\u003c\/b\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cb\u003eOil Ring\u003c\/b\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cem\u003eNote: Piston, circlips, wrist pin, and gaskets are not included in the kit.\u003c\/em\u003e\n\u003ch3\u003eWhy Choose This Aftermarket Replacement?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eDirect-Fit Compatibility\u003c\/b\u003e—engineered to match the bore and ring count of the YFB\/YFM 250 family for a straightforward install.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eOEM Cross-Reference Ready\u003c\/b\u003e—uses standard OEM references and reliable aftermarket cross-refs to simplify sourcing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003ePremium Materials\u003c\/b\u003e—cast iron monometal rings designed for durable wear resistance and consistent sealing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eOS Oversize Correction\u003c\/b\u003e—+0.75 mm oversize restores bore clearance after wear or light honing, helping restore compression\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eComprehensive Ring Set\u003c\/b\u003e—includes top, second, and oil rings to restore balanced sealing and oil control.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eCost-Effective Rebuild\u003c\/b\u003e—an economical alternative to OEM kits without sacrificing sealing performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eInstallation Notes:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eMeasure the bore.\u003c\/b\u003e Verify bore size is within the 71.0–73.0 mm range and confirm that OS 0.75 mm is appropriate for the cylinder before installation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eRing orientation.\u003c\/b\u003e Install the \u003cem\u003etop compression ring\u003c\/em\u003e with the marked face facing upward; ensure the \u003cem\u003esecond compression ring\u003c\/em\u003e sits in the correct groove as per service manual.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eEnd-gap and seating.\u003c\/b\u003e Check ring end gaps after installation and consult spec for OS rings; improper gaps can cause high oil consumption or blow-by.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eLubrication.\u003c\/b\u003e Generously lubricate rings, grooves, and cylinder wall with clean engine oil or assembly lube to prevent scuffing on initial startup.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eRing compressor use.\u003c\/b\u003e Use a proper piston ring compressor to seat rings evenly into the bore without twisting or bending.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eCleanliness.\u003c\/b\u003e Thoroughly clean the cylinder, piston lands, and oil passages before final assembly to avoid abrasive particles causing wear.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhy Upgrade?\u003c\/h3\u003e\n\u003cp\u003eRunning a worn piston ring kit on these 250cc engines invites compression loss, higher oil consumption, and reduced power. Upgrading to this OS oversize replacement restores sealing integrity and bore clearance, delivering reliable compression, smoother oil control, and renewed performance for trail riding and farm work.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"ATV City","offers":[{"title":"Default Title","offer_id":57319264452982,"sku":"192.04804","price":15.33,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0971\/0302\/0406\/files\/pistonring_c9ff371a-97a9-4c3a-bae3-1ffe4d22a295.png?v=1774886130","url":"https:\/\/dgtagri.co.uk\/products\/piston-ring-kit-yamaha-yfb-yfm-250-os-0-75-1989-2009","provider":"DGT Agri","version":"1.0","type":"link"}