I can't post in the performance issues yet, so I will post my question here. I have a victory Vegas 8-ball 2013 and it's been making a gurgling sound at around 15mph and 25mph. When it's first started, it'll make the sound at around 1900rpm in neutral. When I've ridden it for about half an hour at highway speeds, the sound gets quieter but still there. Also, it will stop appearing in neutral after it's been ridden. It is also more prominent when the gas tank is half way full or less. I've taken it to various shops but they said they didn't know what's wrong with it. Any ideas as to what this could be? It only started this sound after my 10k service and I already have 17.5k on it.