This removes the fresh air system that dumps outside air 
into the exhaust system just after the exhaust valves in 
the heads. It will lower your exhaust temps (control the 
blueing of your pipes!) and kill a lot of the backfiring 
during gear changes and decelleration.

Items needed:

* two  1/2 inch rubber vacuum caps
* one   3/16 inch rubber vacuum caps
* one   5/8 inch rubber vacuum cap

You should be able to get all the parts listed at an auto 
parts store, like Pep Boys, Autozone, Napa, etc.


Procedure:

Remove seat (8mm).  Remove speedometer housing (8mm), don't 
forget the cable and wire bundles.  Remove fuel and vacuum 
lines from petcock.  Be sure to put a few rags under this, 
as some fuel will leak out.  Now take the front and rear 
fuel tank bolts (12mm) out and remove the tank.  If you have 
a tire laying around, it makes a nice place to set the tank, 
otherwise place it on a few old towels or your old bowling 
shirt :-).

Locate the hoses between the valve covers... they looks like 
a T and go to a gold air valve. Take them off of the valve 
covers, and place the 1/2 inch  vacuum caps over the ports 
on the heads.  Now, remove the small hose from the gold air 
valve runs to the T fitting connected to the petcock vacuum 
line, and plug it with a 3/16 vacuum cap. Lastly, remove the 
large hose that goes from the gold air valve to the back of 
the air cleaner assembly. Put a 5/8 inch vacuum cap on the 
back of the air cleaner assembly.  

That's it...you're done! Some people have mentioned that they 
could plug these lines without pulling the tank and seat, so 
take a flashlight and have a look at your bike and see if 
you're one of the lucky ones...