exhaust leak & gasket help

[reillypadraig]

hey guys i have been tuning my carbs to no end but i keep getting a backfire and its the exhasut thats the problem, i have a leak at the start of the end can and just realised my exhaust itself isnt standard( i was told standard has a interlinking pipe between some cylinders) mine doesnt, its a 4-2-1 with a scorpian end can. so i bought a standard gasket of the bike and it wouldnt fit? i dont know the bore or the stright lengths or the back pressures of the exhaust system and i cant for the life of me seal it, bike only came with this and not even original clamp? but fits on great????  how could i tell if its a full scorpian system?? exhaust has seen better days and its pitted and rusted. im thinking of just siliconing the bastard up


so what gasket do i need? id need an exact size, as last time i got the size of aj sutton website?