Twin Power™ vacuum piston directly replaces H-D 27585-88 for Keihin CV carburetors on 1988-Up XL Sportster and 1990-Up Big Twin Harley models.

• 40 mm or 44 mm piston restores proper vacuum operation for smooth throttle response
• Fixes worn or broken diaphragms causing hesitation and poor idle performance
• Direct O.E.M. replacement H-D 27585-88 for Keihin CV carburetors