echo pb200 blower slowly descreases idle speed and then dies after about 10 seconds

Ok so I have an echo pb200 that I believe is a 2005 model. Ok so at first I thought the idle speed was too low, but that did work. Basically what happens is that you can run it at full throttle and it will go back to an idle and run at an idle fine for about 15 seconds, but it slowly decreases in speed until it stalls after that. Also if you try to give it more throttle after it gets to the point where it's idling so slow that it's barely running it just boggs down and won't really want to go back to full throttle. Then most of the time if you let it stall it won't want to restart. Any ideas? I'm thinking it just needs a carb rebuild since it is 10 years old. It does need the primer bulb replaced cause it's rotten and about to leak. Not sure if that will cause this problem. Any ideas?