Have just come back from a 1000 mile trip abroad (Assen Moto GP). Whilst there the bike started to run very poorly. The riders I rode with said they could smell petrol when riding behind me. Other symptoms, engine tick over speed has dropped, bike seems to run rich, exhaust note has increased in volume, very poor slow running, engine very hesitant and sounds rough. Where should I start to look for the problem? I only bought the bike in Feb this year? Previous owner had changed the plugs and oil and I have recently synchronised the throttle bodies. It was running fine before I went on the trip. Any advice appreciated