250 inliner trouble shooting

[stringbean25]

i have a slight stumble off the bottom end at an idle, right when i touch the throttle i cuts out like its gona die but if i bump the throttle hard so it stumbles the motor kinda hickups and the rpms will jump up. The motor runs good above 1200rpms its just not below that but it idles good

I had the carb rebuilt (rochester 1bl monojet)
tomorrow i'm gona drop in a napa reman distributor
good plugs and wires i replaced those last year
i set the timing about 8 degrees it runs the best for now right there
i run mid grade with my lead additive

this what i've done so far, next to doing a compression check
can anyone with inline love help a young buck out

thanks