Wizz sound with the shutter speed above 1/50s

[Diomedes]

I have a problem with my Kiev-4m. The shutter speeds above 1/50th are still slowed down by the slow speed gears. When the shutter is cocked, you can hear the slow speed mechanism still present even at the top speeds where this mechanism should no longer be slowing down the curtains.

I've started the problem somehow when I activated slowest speeds and bulb. Till now, everything with this camera works extremely smooth and accurate, even the slow speeds and bulb .
Is there an easy fix to this problem without diving.

Thanks!