[Christ]

I've brazed the power valve on quite a few carbs... on older 4 cylinder cars, it really doesn't affect anything unless you intend on floor it and go - type fuel delivery.

Several Kei-Hin carbs were known for their ability to randomly flood engines when you hit the gas too heavy, too quickly. The fix is to close the accelerator jets off, and use the throttle at bit more sparingly (or listen to a backfire every time you hit the pedal too quick).

The only way that you can run lean by moving the float in the bowl is if the bowl starts to get empty. I find it highly unlikely that you'd get better fuel economy by doing it, considering that no matter how many times I've adjusted the floats on any of my industrial engine carbs, they still run for the same amount of time on the gallon fuel tank they have.

Of course, they're steady state engines, too. Maybe something's different there.