Hey everyone thought maybe would have some advice.  I just bought a 97 yzf 600r a little over two months ago I don't know how long it had been sitting before I bought it which was from a dealer but it ran great the first two months but now two weeks ago I was leaking gas right near the fuel pump so originally I thought I had a hole in the hose that connects to the fuel pump from the gas tank I believe so Instead of cutting the hose to be safe I just bought a new one reclamped it looks great and it stopped leaking for that moment I road it about 30 miles home and thought ok it's fixed.  The next day I go to take it out and find that there is still about a 6 inch puddle of gas dripping below the fuel pump and pretty much stalled out on me half way down the street from my house it would start up again but wouldn't stay running for long and if I put the choke on it seemed to run a little bit better.  So my next thought is it's probably been sitting for a while the seals in the petcock are probably dry rotted and looks as though thats where its leaking from and probably is getting a fuel/air mixture which is causing it to stall after a while.  So I rebuild the petcock yesterday and it starts right up seems like it will be ok.  I almost get to the nearest gas station and it stalls on me again I'm thinking I ran out of gas so I put gas in it it takes a while to start up due to gas getting into the carb get it started but as soon as I roll on the throttle it doesn't rev and really no reaction to rolling the throttle whatsoever.  My next assumption is when I took the seal off that is directly inside the petcock the one with three holes in it it had a very much powdery texture which proved that was clearly the gas leak problem which it now no longer leaks.  My guess is that powder from the seal has clogged the fuel filter and thats why it won't start now.  The only other thing I could think of is I got a two brothers exhaust put on about two weeks ago and if the dealer didn't re-jet it would that cause it to not run?  Otherwise I have no clue what else it could be.   Any advice would be greatly appreciated.

First off, good job in providing a lot of details.... I'm guessing the whole fuel system needs to be cleaned/replaced.  fuel filter, gas lines, carbs, jets, the whole works.  just to be safe. 

It's not the exhaust unless you did the full system with headers and all.  But i'm guessting you just did a slip on.  Even though it would still run if the jetting is a little off.  Did it run at all after the dealer put on the exhaust for you?  Why didn't they look into your stalling/fuel problem when you had it there?

and you said petcock.  lol.

yes I did just do a slip on and it ran for maybe two 15 minute rides after leaving grandprix motorsports which is where I got everything done at....what pissed me off is that I told them it wasn't the gas line because I cut it and made sure it worked and they said I cut it to short so they charged me 89.00 to check something that I told them didn't need to be checked then charged me another 40 dollars to put a fucking 5 dollar hose on I could've done in 2 minutes.  I was pretty upset i'll never go back there again.   And yet it was still leaking the next day which I fixed the leak yesterday now its just everything else.