Top End

• Enhanced piston pin oiling slots, radial boss machining, and annular grooves for improved wrist pin lubrication • Lightweight piston with a tight piston wall clearance for a quieter running engine • Skirt coated for reduced friction and improved break...

Spring kits contain springs and titanium upper collars; lower collars included as required; spring kits are engineered for use with standard and oversized valvesSpring kits come complete for one motorKeepers are not includedMade in the U.S.A. Yamaha --...

Replacement Spring Kit for Kibblewhite Top End Service Kit Yamaha -- YZ 250 F -- (2015, 2016, 2014); Yamaha -- WR 250 F -- (2016, 2015, 2014)

Spring kits contain springs and titanium upper collars; lower collars included as required; spring kits are engineered for use with standard and oversized valvesSpring kits come complete for one motorKeepers are not includedMade in the U.S.A. Kawasaki --...

Spring kits contain springs and titanium upper collars; lower collars included as required; spring kits are engineered for use with standard and oversized valvesSpring kits come complete for one motorKeepers are not includedMade in the U.S.A. Kawasaki --...

Spring kits contain springs and titanium upper collars; lower collars included as required; spring kits are engineered for use with standard and oversized valvesSpring kits come complete for one motorKeepers are not includedMade in the U.S.A. Suzuki --...

Black Diamond? valves feature one-piece stainless steel construction with stellite tips and special impregnation to improve wear properties and reduce friction; White Diamond? valves feature one-piece construction and hard chrome stemsSpring sets contain...

Spring kit is designed with increased spring rates and high lift compatibility compared to the stock springsCompatible with boosted or turbocharged applicationsCNC-machined titanium retainers and Cr-Si dual springs provide valvetrain control at high rpms...

Stainless steel conversion kit includes only what's needed to convert your head to the long-life stainless steel Black Diamond™ intake valvesExtend the life of the valvetrain and intake components by as much as 4x over the OEM titanium partsIncludes...

For shim-adjusted vehicles

For shim-adjusted vehicles

Manufactured from high-strength, T-5 heat-treated, 390 hypereutectic aluminum alloyAllows a tighter fit and longer piston and ring lifeDiamond-machined pistons are held to plus or minus one gram weight and less than one-half-thousandth-inch (.0005")...