How much would the down payment on a 2009 Kawasaki Ninja 250 be?

its brand new, im only 18 but hav a good amount of cash in my bank account for the down payment. since i dont have any credit really my mom is gonna be the co-signer. now i know it depends on the credit to determine what the down payment is. but on average can someone tell me what the down payment would be on a new 2009 kawasaki ninja 250?