in-line elec fuel pump not pushing through mechanical pump

[dbdevkc]

Originally Posted by 69a

2 PSI is more than enough to prime the system (motor off). This will pressurize the the glass bowl, the fuel pump and fill the carb. Switch the electric pump off and start the engine, you will now have the mechanical pump pressure (yours is set to 3PSI) between the mechanical pump and the needle valve on the carb. and negative pressure on the glass bowl. If it is sucking air at the bowl gasket it is difficult to detect.This is why it is important to have a good seal on the glass bowl.
If you have both pumps running you could have 5 PSI at the carb. I'm not 100% sure about that.

I understand what you are saying. And do not plan to run the electric while running. But would having the regulator set to 2 while the mechanical is delivering 3 to the carb - would the regulator constrain the mechanical pump's ability to suck enough fuel to continue delivering 3 to the carb? In other words, might the regulator set to 2 be a bottleneck?