Maybe this question helps. http://www.italki.com/answers/question/80523.htm

as a slang yaru can mean to have sex. やるか？ Informal phrase which roughly translates as "do you wanna piece of me?!" or "you want some?!" in an aggressive tone. Of course, in a romantic tone of voice, it can mean "do you want to have sex?"

やる is more used in coloquial phrases, and it can't be used as する in verbs formed from nouns. ex: ○勉強する (to study) ×勉強やる ○運動する (to exercise) ×運動やる ○苦労する (to suffer) ×苦労やる Also, it means GIVE to a creature that's under your hierarchical status.

meaning at when to do or doing someting (act to do) you can same usuage or meaning for example　テニスをする/テニスをやる　both mean is I play tennis but ～やる has other meaning to give sothing to other for exmaple 本を友人にやる　（I give this book to friend ) little not polite.