Ron Sutton, an SR500 enthusiast from Edwardsville, Madison County, Illinois, USA, has some great info on SR500 carburettors on his website (links below).
To view the article by Joe Minton, ‘Once Over Lightly’, that featured in Motorcyclist Magazine, Aug 1986, click here.
Stew Ross has written a great article on modifying the SR by fitting a larger (38mm) Mikuni VM carburettor. There’s a link to the article on the Reviews and Articles page of this website (this is Members-only page; you must be logged in to view it).