the cable adjustment is just that, on the brakes, carb or clutch, it is for adjusting cable stretch, not the unit's operation itself
the adjustment for the caliper is inside, and is supposedly self adjusting, which is hardly ever the case
pull the 3 allen head bolts on the side of the caliper, romoving it while careful not to rip the gasket, then turn the white cap clockwise a 1/4 turn at a time, replacing the side cover each time, as it pushes on the cap to check adjustment, if it locks up the brakes, you've gone too far, and will need to pull the white cap, get a screw driver in there and undo the drive screw, then try again
this process will need repeated usually monthly to maintain good braking power
when you get tired of doing that repeatedly, only to find it works for like a week then needs redone again, and again
holler at me, i have the real solution..........hydro's