you're gonna want a taller tire than that. at least an 18 inch tall. and the 250r carb is a little big if your bike is just stock
they're a 34mm on the 250r's.
definately need a 34mm intake and a different throttle cable and adapted to the rear intake boot, and as for jetting, i'm doing it now, have a 48 pilot, 155 main and its still rich, this is a no answer question, trust me, i asked a hundred times and got that many answers, it's a test and tune thing till you get it right
you can dremel out your stock carb intake boot so the 34mm will fit......did you get that carb i showed you from ebay that was a 34mm pj same thing i run and it was 50 bucks