jetting ?

i was wondering if you jet something what do you all have to get to this this...do you need to new exhaust if you have stock one? and i have a gas leak that is coming from the drain to and it's like pouring out while it's running and off if i don't turn the petcock to off i did just the floater and it's good and i check the vave float to and it was good but i replace it anyways.. so i'm wondering what in the world else it could be while my carb was out i clean it out with carb cleaner to...does anyone have a clue i'm very tired of watching my gas it the ground and wasting my money on gas when i have this leak please help..... oh one more thing what are you guy talking about when you say this "plug test first" how is this done? just wondering to. :icon_ cry::icon_ cry: