ok so i start out in first gear and lets say im sitting at like 3k i give it gas and there is basically no response. a few seconds later VROOOOOM it kicks in and takes off. now to me that makes me think its getting too much gas and not enough air but what do i know :dunno:  right im a noob.
anyways the bike has a yoshimuro exhaust 2 into 1. guy said when i bought it that it was a rare exhaust and only made for like 3-4 years long time ago when my 1990 was new. Anyways he said it was rejetted, but that i might need to rejet it since he lives in NC and i live in Va.

any ideas?

If you are trying to accelerate from 3,000 rpm you will have a lag.  Keep the engine speed above 4,000 rpm.