Is one allowed to use maaser money as a Bar Mitzvah presant for a boy who is orphaned from his father?
This is an interesting question.
On the one hand, this is not formally tzedakah, assuming that the boy is catered for financially.
On the other hand, it is a mitzvah to hearten an orphan, and although the mitzvah applies primarily to young children, it continues for as long as the child requires heartening — and certainly for a thirteen-year-old.
Therefore, it appears that this will be a worthy cause, just like many others, just as helping disabled children, and so on. It is permitted to use maaser money for such mitzvah-related causes, because there is no full obligation to give donations.
Therefore, provided you don’t have a custom to use maaser money exclusively for the poor, you can use maaser money for the gift.
Apologies for the delay in the reply.
For more details on suitable uses for maaser money, please see http://www.dinonline.org/2010/12/27/suitable-use-of-ma%E2%80%99aser-kesafim/.