How to beat metal kor in jak II?

I cannot seem to kill metal kor no matter what i try. I have no ammo for any gun except the yellow gun (so no peace maker ammo) and i never got the dark giant power so I can't do that one glitch. Is it even possible to kill him with only the yellow gun?
I know about spin kicking and shooting and about holding the button to get a free dark jak transformation at the start of the fight, but I can only get to his third phase at best and by that point I only have a hit or two left.
Like an idiot, I saved at the start of the fight, so I cannot go back to get more supplies or more orbs for the infinite ammo cheat. Do I have to start this game over?