Top End

Manufactured from high-strength, T-5, heat-treated, 390 hypereutectic aluminum alloyAllow 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")...

Manufactured from high-strength, T-5, heat-treated, 390 hypereutectic aluminum alloyAllow 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")...

Includes rings, clips and pinEasy-to-follow step-by-step installation instructions Honda -- CRF250X -- (2009, 2008, 2006, 2007, 2005, 2004); Honda -- CRF250R -- (2008, 2009, 2004, 2007, 2006, 2005)

Manufactured from high-strength, T-5, heat-treated, 390 hypereutectic aluminum alloyAllow 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")...

Manufactured from high-strength, T-5, heat-treated, 390 hypereutectic aluminum alloyAllow 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")...

Includes rings, clips and pinEasy-to-follow step-by-step installation instructions Yamaha -- YZ 250 F -- (2003, 2006, 2001, 2002, 2004, 2007, 2005); Yamaha -- WR 250 F -- (2004, 2007, 2009, 2008, 2002, 2001, 2003, 2006, 2005, 2010, 2011, 2012)

Manufactured from high-strength, T-5, heat-treated, 390 hypereutectic aluminum alloyAllow 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")...

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. Honda --...

• 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 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...

• 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...

New replacement cylinder headInclude cam caps and cam cap boltsInclude C630 (nickel/aluminum/bronze) valve seats and guidesCompetition valve jobShortened valve guides to accept higher lift camsUnshrouded combustion chamberBlended bowl seat to portStock...