[surfsup]

So what you are saying is a two stage should consume more gas then a single stage. But I wonder if that holds true for this carb. I’m not familiar with the 4180 carb except for what has been written, this carb is suppose to be an economy, low emission and performance carb. And in one of the web sites I found, say to change the two stage to a single for performance. So I wonder if the two stage pv is what makes this an econo carb, which would use less gas, and because of the design changes that have been made, the power valve would not operate in the manner that you have described. I changed the single stage back to the two stage; I’ll run a tank of gas and see if my mileage is any better.