RickG wrote: I ran 6 into 1 pipes on mine for years ans never felt that a jet change was necessary. I totally agree with what Kawboy has said about drilling or body modifications, it is a very good way to ruin a set of carbs and they are hard to find nowdays.
The only reason I could think of to go with a jet increase is that if you are doing a lot of riding at above 4000ft
For the record, the higher the altitude the thinner the air and requires less gas to keep the mixture at or near 14 to 1 parts air to gas, so continuous riding at higher altitudes needs smaller jets. Good rule of thumb is to go down one jet size for every 5000 ft. in altitude.