aggressive male kitten

Question
harley is about 13 wks old (have had him for 6 weeks) and he is a terror to us.  he attacks us, bites, scratches, hisses, ears laid back and puffed up tail.  we have tried squirt bottle, light tap ontop of his head and scruffing makes him worse.  he actually comes back at us with a vengence!  he's pooped outside of his litterbox 3 times now and climbs the curtains and chews wires!  nothing seems to affect his nasty behavior, but the biting and clawing are getting the best of us!  he is not neutered, is the answer that simple?  he will let us pet him for about 1 minute and then bites and scratches us badly!  we have even tried ignoring him, but nothing seems to help.  my boyfried loves him, but is actually scarred from the little guy!  what can we do?  please help, we don't want to give up on him!  he has a stuffed monkey that he tries to disembowel regularly!

Answer
Phew Robin, you have quite a problem kitten there ! Please tell me more about his history and then I can give you some ideas to try. But first I need to know more so that we are not training him incorrectly.
what is his history?? was he from a feral/wild cat mom?? was he from a shelter? Was he taken from his mom at an early age?
Please tell me everything about his first few weeks of life that you can think of.
Now, has he been vaccinated? what breed of cat is he? Has he been like this since you first got him .. or has this developed over the last 6 weeks?
Do you have other pets in your home?
Does he appear to be afraid of you? or strangers? or is he more aggressive than fearful?
ie. does he hide under the bed when strangers are over... or does  he go after them with aggresssion?? Does anything seem to start this behaviour? such as loud noises? feeding time? movement? children?etc...
Please... give me lots of info.. anything you can think of...
Thanks, Teresa