yellow rose said

Ok, I’ll play along. Did you even look at the link I posted? I doubt it. If you bought a QF Brawler 950, you didn’t buy a 950. This is why I say do NOT a buy a carb based on CFM.

Here are the numbers so you don’t have to go look them up. This is according to QF.

1.390 X 1.687 is 750 CFM (BR-67302).
1.390 X 1.750 is 850 CFM (BR-67303).
1.450 X 1.750 is 950 CFM (BR-67304).
1.560 X 1.750 is 850 CFM (BR-67314).

That’s QF’s numbers and the part numbers of the carbs. So you tell me how a .110 smaller diameter venturi flows less than the 1.560 Venturi carb unless it has annular boosters, which it doesn’t. It does appear to have a choke on it, but that can’t count for that huge discrepancy in flow.

Oddly enough, if you actually put any of these carbs on a flow bench and tested them at 20.4 inches of water they would ALL flow well over the rated CFM.

That’s why we need to select a carb based on Venturi and throttle blade diameter rather than CFM. That 1.390 X 1.750 will feed a pretty hot engine and not even sweat it. And the driveablity will be much better than either the 1.450 or 1.560 Venturi and I doubt there is 5 peak HP between the three of them.

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