Great!
But i can see on this picture:
http://pallenaldo.googlepages.com/motor_samlet_1.jpg
That you have mounted the original malossi flange on an flat evo-exhaust port. The intension of the conical mounting is to fit perfect on a malossi speed cilinder, and so it will be airtight.
But if you mount it on an evo i will recommend and flat flange (ofcourse angled just like the one you have) See a pic of mine:
Flat on flat with an gasket between.