Snatchy power delivery
 

I've owned my 2008 DRZ400sm for 6mths. It's the ideal apart from one long standing issue. The bike starts first time every time, it then runs well until it's warmed up and then has a really 'snatchy power delivery'. If I stop after a mile or so when it's warmed up and turn the engine off and immediately restart it then the issue resolves itself and the bike runs smooth as silk. It does this every time. My assumption is that there's a sensor somewhere that’s faulty, but then again, I'm no mechanic. Any advice would be appreciated.