Never, ever, ever let him do what he wants if he's not listening to you. If you decide ahead of time to let him go ahead and gallop (although, teaching a horse to rush a jump isn't a good idea), then be sure that you don't wait for him to try. Tell him to do so, and that way he's not winning any battle he's having with you.
Do you know how to do a one rein stop? If not, learn quickly. Every time he goes faster than you want him to, sit back on your butt and yank his head around. Also, I'd suggest getting a standing martingale to prevent him from eating in the middle of riding if it's a common problem you have with him.
More than likely your problem is that he doesn't respect you, not that he's too hyper. But if he respects you all other times, maybe try to lunge him before you get on. Get some of his excess energy out and don't jump him while he's still worked up.