Mabe if you pilot is lean then yes. Also your current main might be too rich with the new pipe. Best way to find out is go ride it with the new pipe and then go from there.
You should prob try it first as it will depend on how close your jetting was to start off with. f.w.i.w. when I switched from the motowest to the fmf on my 300 i had to go up 2 sizes on the main to compensate