250-500cc Smaller carb on the WR250 ???

I have a 38mm PWK that works very well, but can't help but wonder if the 36mm PWK would give me more bottom end...

The bike has plenty of top end and is nearly impossible to stall, but could use a bit more response down low. While in the woods I typically ride in the bottom/midrange, as the top has too much power unless I am out in the open.

Do you people think that switching from a 38 to 36mm PWK would make much difference, or isn't that a big enough change to be worth while?

Going down from a 38 to a 36 will give 14% less-cross sectional area. The net effect of the smaller carb will be to increase air velocity at lower RPM so that it will just work better. It will definitely make a difference, but not a huge one. Your bike will be more responsive a lower RPM (below the ‘pipe’), but not more powerful. It will be more tolerant of larger throttle changes and react quicker to them. Just how effective it will be depends on your riding style. If it seems to hesitate a bit if you ‘whack’ the throttle open, it will fix that up somewhat, but if you tend to be gentle with the twisty thing, it’s not going to make much noticeable difference..

. Ok, thanks for the reply. I hate to bother with the change if it won't be a drastic one.