Well I seem to have fixed it. The fuel line that attaches to the top of the prefilter had an o ring that I didn't replace and I guess it was letting air in. I found an o ring I had laying around that was just slightly bigger than the one that was on there and after a quick reassembly and prefill of the filters it fired right up with almost no provocation from the throttle. I'm glad it's running fine now, but a little worried at the same time knowing that if one o ring fails to seal the engine won't run at all.