Keihin velocity stacks improve the air flow into the carburetors by smoothing small eddy currents that develop near the intake bells of carburetors, especially during high intake velocity conditions.  This not only increases horsepower by improving combustion but also increases throttle response and fuel atomization.  These stacks will fit all Keihin FCR28-41 flat slide aftermarket carburetors.  The length of this velocity stack is 50mm (blue stack) which promotes better torque and mid-range response. Includes mounting hardware.

Lengths are also available in 30mm (red stacks).  Choose your length depending upon your clearances and tuning requirements.  Shorter lengths relate to less restriction and higher RPM power whereas the longer lengths smooth flow more and provide higher low RPM torque characteristics.  Velocity stacks are sold each. 

PLEASE NOTE: There is still limited availability of the blue 50mm velocity stacks for FCR28-31 carburetors.  Make your selection above before adding to your cart

Looking for the shorter red stacks?  They can be found here: Red Velocity Stacks