DescriptionHusqvarna® FS 450 2017-2018 Husqvarna® FX 450 2017 Husqvarna® FC 450 2014-2018 KTM® 450 XC-F 2013-2017 KTM® 450 SX-F 2013-2018 By taking advantage of the latest development in valve spring wire chemistry and manufacturing techniques, KPMI® has developed ovate wire Beehive style springs that will live and perform at a high level in Husqvarna® and KTM® applications. By coupling these developments with strict KPMI® design protocols and employing multiple design simulation and FEA analysis software, we were we able to overcome the torsional stresses unique to ovate wire springs that previously limited their operating parameters. KPMI® Beehive Springs are progressively wound using Kobe Super-Clean chrome silicon based wire that is heat treated and shot peened. KPMI® uses its tightly toleranced, FEA designed hardened Titanium retainers in these applications to ensure correct assembly height and resist keeper pull through. The hardened steel basewashers included in these kits are designed to locate the spring and control lateral movement.Installation InstructionsClick HereTypeIntake / ExhaustRetainer MaterialTitaniumValve Lift0.435″Installed Height*1.360″Seat Pressure80#Open Pressure205#@ Lift0.435″Note*The oem keepers require force to seat fully into the retainer. To correctly observe the installation height, the assembly should be measured under spring load.