I might be buying my friend's 2000 zx6r in the very near future. he left it at the house and i have been riding it for about a week now with no problems. today i hop on the bike and start her up and it dies if i try to give it any gas. i let it sit at idle for a min and then it died on its own. i start it about 4 or 5 more times and it dies every time when i try to give it any kind of gas. finally i got it started and it was fine from then on. any ideas?