Carburetors CFM - CV VS Conventional Flow Rates?

[TxGSrider]

Just out of curiosity, does anyone know if there is a place to find the CFM ratings of the various carbs used on our bikes? I know the cv carbs flow allot less than the same size conventional carburetor counterparts (that big butterfly valve and shaft blocks up allot of the throat area) but how much less?

Is there a rule of thumb even, like a 33mm conventional carb is about the same as a 36mm CV or something?

[gearhead13]

I have heard that is a 3mm difference. A 36mm comparable to a 39mm with butterflies etc.

[TxGSrider]

I have heard that is a 3mm difference. A 36mm comparable to a 39mm with butterflies etc.

On cars they used to "add 10% for vacuum secondaries" but they are measured in CFM to begin with and they were less likely to become over carbureted due to the CV style secondaries.

It'd be nice to find some actual CFM measurements for our carbs (both the CV's and conventionals).

[Big T]

IDK about CFM ratings, but GS 1000 went from VM 26 to BS 32 with no change in HP rating

[850 Combat]

I prefer the easier throttle pull of the CVs over the slide types on my GS. It makes a difference in comfort after a while.