Bait caster centrifugal brakes slip

Hello all, I'm having an issue with three bait casters that I can't seem to figure out and was hoping y'all could save me. I got started with baitcasters 2 year ago with the Pinnacle plat+ which served me well with a few hundred fish until the anti-reverse became unreliable. Picked up an Okuma Calera at a pawn shop for 30$. This model has all three braking systems and really lets me tune in on my casts, then got two of these Wright and Mcgill reels at Wal-mart on clearance for 25$ each. Now the only time I ever back lash is when my settings adjust themselves. Every 30 casts or so the dial under the plate on the reel will drop down to 1 or 0 and I will have a free spinning nightmare after whipping a cast. All three baitcasters are different models, and yet they all have the same problem. Is there a bolt, screw, or lever that will lock or tighten it down somewhere?