Easy things first, carb floats sticking, that can cause fuel overflow. Can be easy to remedy, tap side of affected carn lightly with wooden or plastic screwdriver handle. Use a hefty dose of redex petrol fuel treatment. Often this can sort the issue with minimal expense or effort. My cb500/4 did this every 6 months or so, especially if not used for a week. And these measures invariably worked. If they dont it does need further investigation. Also good to be in the habit of always turning fuel tap off when bikes not actually running. Regulators and rectifies normally separate units on these bikes unless upgraded to modern unit. Sort that out before chasing other potential issues. Not very unusual for battery to be faulty even if fairly new.
