OK thanks. I has mine or i should say was set at like 5 it went to around 3 psi. i sdidnt have any toodl but manage to finagal the reg up to about 6 ran around 3.5 so i want to run about 7.5 to 8 i want that pressure around where you are sounds good thankyou. I can say this luckey your running a siingl 850 these dual quads with mech. 2nds love o drink. I understand though it is a 509 and has a large combution chamber on it so i believe the duals were nessesary

I just went through a similiar situation.

The BG carbs are a great piece. BUT BUT

They have tuneable air bleeds that control the amount of vacuum that basically controls the fuel curve. As the air bleed is enlarged, it will not only work to lean out the mixture, but delay the discharge of fuel at the booster. ie lean spot

Conversely, reducing the size of the air bleed size richens the mixture and activates the main metering system ealier.

SO your 850 is a 2 circuit carb High speed air bleed and idle air bleed. The high speed air bleed which is where you are having the problem is where you most likely want to activate the main metering circuit earlier. You should have .033 air bleeds, Try .028's

Look up the model carb on line and it will have tech specs.

Look at the HS air bleed.

Hope this helps.

Are the power valve circuits on your carburetors boost referenced?
Power valves provide more fuel when there
is no vacuum at the base of the carburetor, but with a blower, there will always be some vacuum, so the power valves
will not function properly.

Hey Al what is the name of your pump and where did you get it from. Its a manual? or electric?