I don't think there are any scientifically set standards for maximum consumption of sugar. And anyway there are various sugars you can eat.
What I would say is replace refined sugars with fruits if possible. Your diet should be based on complex carbs, lean protein, and healthy fats, and you can include some sugars especially in the morning and right after exercising without any fears of bodyfat gain.
There's no RDA requirement for sucrose. They are calories that provide energy and nothing else. If they are over and above your expenditures, the sugar will be turned to fat. If you are trying to gain weight, csugar will help; otherwise less is better.
There's some evidence that a high sugar consumption contributes the Syndrome X and Diabetes Type2.
apparently a serving should not have more that 8g of sugar...according to a talk show on health that was on tv.i'm just conveying the message that was told (incase ppl jump down my throat,hehe)
enjoy ya day!