trx300 4x4 dies when throttle is pressed.

I have a 99 fourtrax that has been sitting for awhile that I am having problems with. If I choke the quad I can get it to start, but it will die once I unchoke it no matter how long I let it warm up. In neutral, slightly choked it will continue to run. Once I put it in gear it will run (stil choked), but dies once I give it any throttle.

the carb is the obvious suspect, but thought I would get some suggestions before tearing in to it. Also reading the forums I see some suggestions of sea foam, should I try adding some to the tank and letting the bike run idle for awhile or start in a different direction?