Denny, I respectfully disagree with the float weight and length being a factor in figuring fuel pressure.

JMHO, the float operates the needle and seat valve by a fulcrum (leverage), and the float itself is a buoyancy factor (moved by the fuel). When fuel is used from the float bowl, the float drops opening the needle valve allowing fuel to enter and refill the bowl, as the fuel fills the bowl it raises the float pushing the needle shut stopping fuel entry. While inertia may play into the weight and length factor, I can not see how either float weight or length would dictate the minimum fuel pressure required.

And, while most carburetor manufacturers will specify a maximum pressure, it should not be confused with normal operating pressure. Though, I have seen manufacture’s tech support tell people to raise their fuel pressure, usually it is due to a poor fuel supply system and a tech trying to make it work with what they have, seldom with optimal results.

Excessive fuel pressure is the number #1 cause of carburetor troubles. High pressure will push fuel past the needle seat and flood the motor.

Again, no disrespect is intended, I truly respect your knowledge and experience. Simply want to clarify and help avoid problems and misunderstandings about carburetors.

I’ll modify my original comment to; “no STREET operated carburetor needs more than 4-5psi.”

BTW, excellent breakin procedure.