[Gator67]

Originally Posted by scott70

The robbmc mechanical pump has to have a regulator with it. I didn’t realize that,, they used to be self regulated but they changed it a few years ago

Interesting. This seems to contradict the information on the website/instructions, which indicates a regulator is not typically needed with the 550hp version of the pump (it is needed on the 1100)...it says 7psi +/- 1 and that using the vapor return should reduce it by 1psi. This seems to be in the ballpark of what I need for a Qjet. Was your experience different?

The instructions also suggest that if a regulator is needed, it should be a non-return version placed between the pump and carb. The problem here is that I seem to recall to function correctly, the pressure to the regulator should be like 3psi greater than the desired pressure.