FZ6 stalling on tick over

[Pjc2480]

Hi all, some advice is required from all you knowledgeable people out there. I was about 20mins into my journey when I had to stop in traffic. I put my 2004 fz6 into neutral and then it stalled.  When I started it again it stalled. The only way I could keep it running was to keep the throttle open slightly and keep the revs up. If I let it back on tick over then it would stall again. I must say that it always started again. 
Could it be that I've over filled the tank as it does seem a fueling issue.  Any help great fully appreciated.  :'(