Not getting enough gas?

by Moe
(Columbus, Ga)

Hello!
Let me start off by saying that I have been riding for 7 years and am now 24 and have never had this problem with past bikes, so it's not that I'm not warming it up enough or anything. I just purchased a 1982 Yamaha xj650 Maxim that may not be the best bike but I love to ride and I love it because it lets me :). Although, it seems that my bike is not getting enough gas when I'm in 1st gear. It will be going and all of a sudden want to die and I have to give it the gas(I know how to let clutches out and when to shift). I recently had it repainted and was worried there was something in the tank so I drained it and cleaned it. I also replaced the hose that goes from the tank to the filter (the clamps aren't too tight) but my filter doesn't seem to want to fill, and on top of that I also just cleaned out the carburetor. Perhaps the intake manifold and how to fix it? I don't want to take it to a bike shop because they charge way too much...Please help!
Thank you, in advance :)