you really dont get it, do you?
the carburettor is jetted so the correct air fuel mix is delivered to the engine.
your thread is entitled "four stroking like an SOB" or summink like that.
that means it was TOO RICH to start with. the jet, as supplied, is TOO LARGE. they do this so the engines will ALWAYS run, with no lean issues.
you have NOT changed your jet. this is the FIRST thing you do, with or WITHOUT alterations to the engine.
by having the small leak, you have LEANED the mixture out.
you arent getting more air into the engine, you are reducing the amount of air passing through the carburettor. the carburettor will still keep the same air/fuel ratio it had previously.
the mixture downstream of the air leak is therefore CORRECT as the leaking air and airfuel mixture combine and enter the engine.
the normal way of achieving the correct mixture is by CHANGING THE JET, and NOT having an air leak.
but, if you want to put a hole in your manifold, and allow dirt and grit into your engine, which travels through the crankcase, destroys bearings, cylinders and piston rings simply because the idea of JETTING CORRECTLY is too hard to comprehend...
GO FOR IT!
enough said...wheres my wall? i feel like bashing my head against it for a while.
im sure you wont listen to the idea of reinstalling the tuned pipe, and rejetting to suit it. because you dont appear to be interested in doing things the RIGHT WAY.
P.S. i have one pipe that likes a 45 size jet! that is less than half a millimetre! the standard jet is usually around 70.