DescriptionValve, Black Diamond™ Stainless, Std. Exhaust, Honda®, CRF™ 250R, 2010-2015All KPMI® Black Diamond™ Stainless steel valves are impregnated by a special German process to a depth of .002”, with a surface build up of .0002”. This Black Diamond™ process improves wear properties, reduces friction, and provides resistance to corrosion and wear that is superior to chrome and nickel electrolysis plating. Each valve is designed using Finite Element Analysis software, and profiles are tested on our computerized flow bench. Black Diamond™ Valves are lightweight, strong, one piece forged with profiles that provide excellent flow characteristics.TypeExhaustMaterialBlack Diamond™ StainlessCoatingBlack NitronegQuantityPkg. of 1Head Diameter25.00mm / 0.984″Stem Diameter4.5mm / 0.1760″Tulip20ºOverall Length3.310″RemarksStandardReplaces OEM P/N14721-KRN-A40NioteThese valves are intended as O.E.M. replacement valves and are completely compatible with the O.E.M. spring kits.  However, experienced engine builders, who are running aggressive camshafts or higher than factory RPM’s may find the combination of the O.E.M. Style Valve and KPMI’s Lightweight Racing Spring Kits advisable. All titanium valves are (Tensilite®) PVD CrN coated, and all stainless valves are Black Diamond™ coated. Must use Kibblewhite® Lightweight Valve Spring Kits when installing Black Diamond™ Intake Valves.Unique Identifier No.FR327789_01GAUS