I have a 2007 Night Rod Special that suddenly started running VERY rough and backfiring. It starts right up and idles fine. But when you take off it acts like its starved for fuel. It will smooth out a bit after you ride a few miles but still doesnt run right. It doesnt have the pick up speed it use to have at highway speed and it cuts out like its running out of gas. I changed the plugs (they looked fine) and changed the throttle cables because one broke. The only other issue with the bike is that the fuel gauge stopped working several months before this problem started. Any suggestions what I can look for?