99 gsxr carb problems HELP!!!!
i have a 99 gsxr 600. i have had bad luck with getting this thing running right. i took it to a mechanic, and he just made it worse...definatly will not be going back to him, but anyways, i found a good friend who works on these bikes. had him clean and resynchronize the carbs. the bike has yoshi pipe and headers, and k&n filter. so we rejetted it to what the recommended jets are for these custom items. now i am having a problem with the bike running extremely rich, (shooting flames out the exhaust). also when i start it, the rpms stay at around 4-5k for atleast 30 seconds, and then when i mess around with the idle adjustment, it goes down. everytime i rev the bike up, the rpms stick at around 4-5k until i let out clutch. but then when coming to a stop, it will die. we replaced the needles in the carbs, and made sure it was jetted right. what could be causing this problem? any help would be great, thanks!!!