If this is the 750F with the rear disc brake, makes sure the brake fluid is not low in the rear master cylinder.
If it is the 750K type bike with the rear drum brake: 'skipping' over rough road surfaces is normal for the type of brake Honda (and almost all Japanese road bike makers back then) used. It is a non-floating rear brake hub. However, if the rear shoes are getting worn (past 1/2 of the adjustment on the long adjuster rod) then the rear brake shoes need to be replaced as they are not gripping evenly, but 'snatching' during uneven road braking. Also: if the rear shocks are set on "soft" (lowest setting) and you weigh more than 100 lbs, put them at least 1-2 notches higher with their adjusters. Your rear shocks may be worn out, with no damping, if they are OEM versions, still. If so, they will have chromed covers over the top half of the shock. When set too soft for the weight the bike is carrying, the rear wheel will be overly active up-and-down over bumps.
