Wilsons Sandbox

Hello fellow listers. Today I recieved and installed a Cobra ISDE muffler in replacement of the "swiss cheese" modified tweety bird muffler. The dealer stated that I should rejet the carb and increase main jet about 3 sizes or it will burn up..... I know that until I do this the bike will be running a little lean, but how much should I worry about this? Ride it a little, don't rev it a lot, or don't ride it at all? My gut says ride it and don't worry, just rejet it as soon as possible to achieve the full affect of adding an aftermarket exhaust. After all, I bored 4 large holes in the factory muffler and rode that for 1200 miles with no rejet. I'm also wondering about the jet size increase. Is an increase of 3 sizes the norm or does this depend on the pipe/muffler being used, etc. One last note, the new muffler sounds great! I can't wait to get to work and romp it through the parking garage. The good thing too is that muffler has the all important spark arrestor so I can still ride the trails without being slapped with a fine. (Yes, I have been stopped twice and questioned on the old "swiss cheese" muffler, riding on state land.) Thanks everyone in advance. I am seaching the archives for some basic rejet data, but was looking for personal opinions/experiences. Thanks again, Rich A12 "Beast" 9000 miles and love this bike!