[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.

[scott70]

Originally Posted by Gator67

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.

Yes sorry… the 1100 pump used to be adjustable and they did away with it the save on costs.