How can I get my 8 month old kitten to stop attacking my older cats?

I just adopted an 8 month old male kitten (about 11 pounds). I already had a 6 yr old female (only 7 pounds) and 16 yr old male (19 pound maine-coon mix). I had the cats separated at first, but they seemed to get along well right away. There was no hissing through the door, a lot of curiosity on all ends, and when they saw each other, no one would attack. So they remained separated for just a few days. I stupidly umed the kitten would be calming down at this age, but I was wrong. He wants to play all the time and the older cats want none of it. He is especially interested in the 6 yr old because she's smaller, faster and somewhat playful herself. When he is awake and in the same room as her, he does not give her more than a minute's rest. Whenever he attacks, she hits him, hisses, growls and runs away. She is truly upset, but the kitten thinks she is playing, so he doesn't give it up. She has taken to hiding whenever he is around and her quality of life has gone done dramatically. I know the 8 month old was weened early, found without a mother or litter mates at 4 weeks old, so he may have never learned what kind of cues from other cats mean, "quit, I've had enough." How can I train him to stop pestering the 6 year old?