Is there any mods on the bike? when you say you raised the needle I assume you installed the e-clip in the bottom grove? if it was put in the top grove of the needle it would starve the engine of fuel making it run lean. you can also try to fine tune it with the air-fuel mixture. Just remember where you started. they usually come with the e-clip in the middle grove of the needle and the air/fuel mixture around 2.5 turns out.