popping

Just a quick one, recently purchased a full fat cup 200 and I have noticed it burbles and pops in about 5 second bursts at idle quite a bit. It isn't loud at all (sounds quite good though) but I'm just a bit concerned that the root of this could be a fuel flow/combustion issue. Anyone else...

I did a little search but couldn't find what I was after... I've noticed that my car pops when letting off above 3.5kprm and giving it a quick blip. Since I don't know the history (mods) of the car I was wondering... what would most likely cause this? The only mods I know of are the KTR...