It would be easier for them to explain the difference than me.<br />From the Boyesen Reed page:<br /><br />"But Boyesen found that the single-stage design incorporated in standard metal and fiber reeds had its drawbacks. \"One reed is not versatile enough to be truly effective at all points in the engine\'s power band,\" he explains. \"A thin, flexible reed performs well at low throttle but not at high rpm. A stiff reed performs well at top end but not at lower rpm.\" <br /><br />Boyesen Power Reeds incorporate an ingenious two stage design. \"The Boyesen design features a stiff primary reed with a port (hole) in it, overlapped by a flexible secondary reed controlling the flow through the port. A specially designed \'rev plate\' holds the assembly in place on the engine\'s reed cage,\" Boyesen explains. The rev plate replaces the engine\'s standard reed stop. <br /><br />\"With double reeding, performance is noticeably improved across the board, from idle to top end,\" Boyesen says. \"the two stage design allows our reeds to respond to any change in air/fuel flow as you accelerate or back off the throttle. There is a very definite increase in performance all across the power band.\" <br /><br />Boyesen says the bass boater who installs Power Reeds in his outboard can expect smoother idle, without coughing or sputtering, improved hole shot, dramatically increased acceleration, quick engine response to even slight throttle changes, a 100 to 300 rpm increase top end (with a corresponding increase top end speed) and increased fuel economy, due to better fuel atomization."
