How do you fit a fuel pump regulator?

[higgy]

I agree on the warm air,when it gets below 50f(10c) the idle jetting needs big changes to richen up the mix
Let me know if you get the 4.5's from Pierce,I was told some months ago they could not get them.ended up getting the ferarri part from fast road cars in the UK

[romus]

...In the end I took the regulator out,...r

Didn't work in the return line because if end to Carb facing to Carb guage read 5psi and the other way 0psi. Even tried at place B and D, but was 0psi (orginal problem of bike not starting explained then! Must be the way the pressure works with the return line system!. So, next option would be to try the Holley at the T junction - but...

But maybe as you took yours out I will leave it. I tested normal pressure with no regulator to be 1.5 - 1.8psi, so actually shouldn't be an over pressure problem, should it? Also if 1.8psi, I don't see how the Holley increases it - I mean, I would have thought the Pressure Regulator purpose decreased pressure in a controlled way!?

To understand these different fuel lines, first I checked and confirmed that the fuel pump is the same part number on the 750 and 906 Paso.

The 750 Paso fuel line setup, looks like a loop after the fuel pump back into the line that comes from the tank - that line from the tank would be less pressure so then the fuel path will do another pass through the filter. Surely the affect would have some reduction in the pressure - someone will know what a 750 pressure at the carb is without a fuel pressure regulator, but I expect it is over 3.5psi, so then installing a pressure Regulator would reduce the pressure to ~3psi. I saw some people put it in the line by the carb, which would work sice the return line is a loop and not actually into the tank.

The Paso 906 has a return line that goes back into the tank at a different connection point and this system for sure reduces the overall standard pressure to the carb - my test was ~1.8psi. My test is that if the reurn line is blocked it brings the pressure up to 5psi at the carb, so that means the fuel pump for the 750 and 906 creates that amount of initial pressure. Then with the 906 return line open, the pressure at the carb drops to ~1.8psi - meaning because of the effect of the return line through the tank. Now, as I understand it a Fuel Pressure Regulator reduces and controls that reduced pressure, so there is no point in having a regulator for a paso 906! And so the 906 pressure at the carb is actually fine at ~1.5-1.8 psi, which from other information I have is acceptable.