Did some searching on the forum to find out what jets and air/fuel screw combinations people were using but I havent seen many specifics.

Recently installed my 39mm FCR's and played with the acc pump delay and needle settings. Also tweaked my air/fuel screws some with minimal results. The quad currently has a really big delay in power off the bottom. I dont see this much when racing because the thottle is near wide open or close to it and there real isnt much roll on needed, but in all gears the bottom end of the rpm spectrum is really lacking. Im sure that the squirt of the acc pump isnt hitting the slide which I have heard is really common, I checked this and did end up adjusting my delay a little bit. Needle is currently at the 4th notch from the bottom, jets are 140s I believe (stock) and fuel/air screws both at 2 1/2 turns.

If I stab the throttle hard when its at idle it will fall flat on its face, or at least stumble some then recover slowly (1.5 seconds or so) till 4-5k rpm. With the old BSR42 Mikuni throttle response was near instant and smooth throughout the rpm spectrum.

So to sum it up, my low rpm power sucks, mid range is decent, and high rpm 6.5k-9k is huge.

Is there any way through carb tuning I can make this work or is it just due to the combination of upgrades I have done Im stuck with a high rpm powerband?

 

I really like my FCR's but if you wack it open off idle it will fall on it's face- thats normal- the key is to keep the revs around 1800 ( idle )
and than you can get a feel for how fast you can twist it open. I have no hesitation at all and a very strong bottom end-
I played with the acc pump as well and ended up putting it back to the factory position - the stock mains are 160's I believe and I have my needle clips at the second to last slot on the bottom. air screw sound about right - you might go another 1/2 turn richer
I am at 4500ft
I tune my air screws at night cause that's when I can see if my head pipes are glowing or not. Get enough gas going thru that circuit to keep them from turning red in the dark and you should be fine and the fan will come on a lot less frequently.
With the stage 3 head work and cams youv'e had done you will feel a loss in the bottom but the top will be a great ride
good luck
there are some excellent tunning guides for the fcr's on line just do a search.

 

Sounds like you might be a little lean, I have the 160's in mine with the needle clip on the very bottom. I do have a lag in the bottom end of the throttle, but like major said just keep the rpms high and you won't have a problem. I have disabled my accell pump.