2004 vtx1300r, 22k miles. I'm no mechanic but can youtube pretty well and enjoy doing it. Bike had a hard time starting and would not start about half the time and backfire when it was running. My frustration lead to the bike sitting in the garage for the past 4 years. I recently changed the oil, coolant, spark plugs and fuel. Cleaned the jets and replaced the battery about a year ago that is on a battery tender. The bike tries, but will just not turn over. I received an auxiliary fuel tank to help with troubleshooting. When I insert the auxiliary hose into the fuel hose and place a golf tee in the air vacuum line, it starts right up. I do notice fire coming out of the exhaust pipes when idling. The petcock was leaking and I replaced it. The old petcock was deteriorating inside the tank. I just don't know where to go from here. Any help would be appreciated.