I'm not sure the drop would cause the RC valve to move, as it is goverened by the ignition unit and is moved relative to engine RPM. You may have caused other damage which actually means the valve isn't working at all, so the bike has lost the lower power produced by the valve. This would mean you get more of a kick higher up as the enigine comes into it's powerband.
Have you removed the fairing and checked the valve rotates? If it doesn't I'd start by checking the cables from the valve to the motor, and the wires to the motor itself.
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
