Quad Bike Carbs?
 

I've seen dual, dual Weber 45 DCOE's (for a total of 4, 45mm intakes) on some
7's. Is that over-kill? I ask cuz I see a lot of people using just the Weber 51mm IDA which only has 2 51mm intakes. So how about a set of 4, 41mm down-draft (maybe even smaller) bike carbs, like: Keihin FCR's or Mikuni RS's? Would
they flow enough for: BP'd 12A or a BP'd 4-port 13B?? Where can I find this info in laymen's terms? Thanks.

I have seen twin Weber 36's or Mikuni's, but a twin 45 would be monster overkill for most applications. Hell, even boosted!

It all depends on your application. I have a 48 IDF on my half bridge 13B and it is almost too small. I have that carb maxed out for flow as far as adjustments go. I was considering going to either a 51 IDA or a dual 40 IDF setup of some sort.

I also have seen dual 36's & a few set ups using dual 48's. I think Rotary Engineering & Killer Bee Racing had dual IDA manifolds. I have seen Hogan's Racing manifolds with twin IDA's.

personally, if i were you, i'd keep it simple and start with a single 51 IDA. it may not flow the most, but it has time on it's side. it's proven! i'm not trying to discourage experimentation, but if you're just starting out on this road, i can tell you that tuning twins requires skill and it's probably not where you want to begin.

however, if you're dead-set on the idea of going with twins, you may want to start with 40s. i would tend to think 36s might be small for bridgeys. i, too, think twin 48s would be overkill, but i honestly don't know.

I've always thought dual 44 IDFs would be an interesting setup.