I recently purchased a 2006 Magnum 330. It had been sitting up for about a year. I have put new gas in it, new battery, ran some sea foam in it, and it will only run with the choke part way out, but at times wants to pop, cough, backfire? Does it have a in line fuel filter somewhere that might be clogged and not letting the fuel flow? It acts as if it is not getting enough fuel at times? Any suggestions would be helpful. It only has about 400 miles on it, was owned by an older couple that never got it in the mud, just road it around their home.