{"product_id":"yamaha-yfm-oversize-piston-kit-yfm-350-yfm-400-f-fw-fb-os-0-75","title":"Piston Ring Kit OS 0.75 – Yamaha YFM350 \/ YFM400 Big Bear \/ Kodiak \/ Bruin \/ Grizzly \/ Raptor \/ Warrior \/ Wolverine (1987–2011)","description":"\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eUpgrade the heart of your Yamaha YFM 350\/400 engine with this Oversize OS 0.75 Piston Ring Kit, engineered to restore compression and seal in rebuilt engines across a broad range of YFM models. It is designed for cylinders that have been overbored to the final OS 0.75 specification, delivering reliable performance when trail work, hunting, or farm duty demands more from the motor. This OS 0.75 piston ring kit is a practical aftermarket replacement that helps you reclaim throttle response and steady power without the cost of OEM parts.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eBuilt for durability under demanding off-road use, this oversize piston ring kit targets the common wear points that plague overhauled 350\/400 engines—loss of compression, reduced power, and sloppy low-end torque. The OS 0.75 specification ensures a precise ring gap and seal after overboring, maintaining reliable ring seal and consistent combustion. In rugged trail and farm scenarios, this replacement helps you regain the predictable power curve you remember from your machine's early days.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eComprehensive Vehicle Fitment\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"ds-scroll-area _1210dd7 c03cafe9\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cspan\u003eManufacturer\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan\u003eModels \/ Series\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan\u003eYears \/ Details\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350ER Moto-4 350\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1987–1995\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350U Big Bear 350 2x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1987–2000\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350F Moto-4 350\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1987–1999\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350FW Big Bear 350 4x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1987–1999\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350FX Wolverine 350 4x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1987–2009\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350X Wolverine 350 2x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1987–2009\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350G Grizzly 350 2x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e2007–2010\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM350R Raptor 350\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e2004–2009\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM400F Kodiak 400 4x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1993–2006\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM400FW Kodiak 400 4x4\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1993–2006\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYFM400FB Big Bear 400 IRS\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e2007–2011\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e \u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eProduct Specifications\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"ds-scroll-area _1210dd7 c03cafe9\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cspan\u003eAttribute\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan\u003eDetails\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eOEM Reference Part Numbers\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003e\u003cspan\u003e4GB-11610-40-00\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e4GB-11610-20-00\u003c\/span\u003e\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eType\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003ePiston Ring Kit (OS 0.75 Oversize)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eManufacturer\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eAftermarket Replacement\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eApplication\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha YFM350 \/ YFM400 series (1987–2011)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eOversize\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.75 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eBore Size Compatibility\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e83.75 mm (final bore after machining)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eMaterial\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eHigh-strength metal alloy; chrome-faced top ring\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eCondition\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e100% New Aftermarket\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e \u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eOEM \u0026amp; Aftermarket Cross-Reference Information\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"ds-scroll-area _1210dd7 c03cafe9\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cspan\u003ePart Number\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan\u003eBrand \/ Type\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan\u003eCross-Reference Notes\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan\u003e4GB-11610-40-00\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha OEM\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eOEM reference for 0.25mm oversize rings; this OS 0.75 kit is the next step for rebuilt engines.\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan\u003e4GB-11610-20-00\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eYamaha OEM\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eOEM reference for 0.50mm oversize rings; this OS 0.75 kit serves as a direct oversize replacement for further wear.\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan\u003e192.04811\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eAftermarket Replacement\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eInternal product code used by some suppliers for Yamaha YFM350\/400 ring kits.\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e*\u003cspan\u003eOEM cross-reference numbers are provided for reference purposes only. These numbers indicate the lineage of oversize rings; always verify your final bore size (83.75mm) before ordering.\u003c\/span\u003e*\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eWhat's Included\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eThis OS 0.75 oversize piston ring kit ships with the essential components to rebuild one Yamaha YFM cylinder.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eTop Ring (chrome-faced)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eSecond Ring\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eOil Ring Set (including expander spacer)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cem\u003e\u003cspan\u003eNote: This is a piston ring kit only. It does not include the piston, wrist pin, circlips, or gaskets.\u003c\/span\u003e\u003c\/em\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eWhy Choose This Aftermarket Replacement?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003ePrecise Oversize Fit:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Specifically designed for engines with a final bore size of 83.75mm (OS 0.75), ensuring correct ring gap and optimal sealing after overboring.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eOEM Lineage Cross-Reference:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Follows the oversize progression of OEM rings (0.25, 0.50, 0.75), making it the logical next step for a professionally rebuilt cylinder.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eRestores Compression:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e New rings restore proper ring tension and seal, directly addressing power loss, blow-by, and high oil consumption.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eDurable Construction:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Features a chrome-faced top ring for superior heat resistance and wear longevity, built to withstand the demands of high-revving engines and tough terrain.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eComplete Ring Set:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Includes all three rings (top, second, and oil ring set) required for a complete piston seal.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eCost-Effective Rebuild:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Delivers reliable performance at an aftermarket price, ideal for extending the life of your machine without a full OEM investment.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eInstallation Notes:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eVerify Bore Size:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Confirm the engine cylinder has been professionally overbored to the final size of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e83.75mm\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e before ordering. This kit is not for standard or other oversize bores.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eProfessional Machining Recommended:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e A proper overbore and hone by a qualified machine shop is essential for the new rings to seat correctly and achieve a long-lasting seal.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eCheck Ring End Gap:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Always check and adjust ring end gaps according to the service manual specifications after the bore is confirmed.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eLubricate Before Installation:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Lubricate the piston, rings, and cylinder wall with clean engine oil or assembly lube prior to installation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eOrient Rings Correctly:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Ensure rings are installed with the correct orientation and that the ring gaps are staggered according to the service manual to prevent blow-by.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eFollow Service Manual:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Adhere to all torque specifications and break-in procedures outlined in the Yamaha service manual.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eWhy Upgrade?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan\u003eRunning a worn-out piston ring set in a bore that's already been worked over compromises compression, throttle response, and reliability. This OS 0.75 oversize ring kit restores proper compression and consistent power delivery, helping your YFM 350\/400 run reliably through tough trails and demanding work. A fresh ring seal reduces piston slap and the risk of scoring, reducing the chance of a sudden loss of power on rugged terrain.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan\u003eOrder your piston ring kit today and get back on the trail with confidence.\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e","brand":"ATV City","offers":[{"title":"Default Title","offer_id":57319264616822,"sku":"192.04814","price":19.33,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0971\/0302\/0406\/files\/pistonring_9053938d-e8c0-495d-8364-76398d512f07.png?v=1774886127","url":"https:\/\/dgtagri.co.uk\/products\/yamaha-yfm-oversize-piston-kit-yfm-350-yfm-400-f-fw-fb-os-0-75","provider":"DGT Agri","version":"1.0","type":"link"}