I have a bosch type elec fuel pump. does 330lph. I am going to be running the fuel past the twins and back to tank through the return line. The return line is a slightly smaller dia which will create a little pressure to the carbs. (this is how i understand it).
So do i need to run a fuel pressure reg or will this bypass system be enough?
 
Thanks.
Darren.

No one??

Is it a low pressure fuel pump? 5-6psi or so?

Pump is too big for the job.get an appropriate pump for the carby application and it will be much easier to set up.

From what i can gather - around 75psi - which sounds like alot.

yeah, thats way too high to be running on carbs as it sounds like you've got an efi pump.
You'd only want a pump running around about 6 psi i reckon (from when i had twins) and i think it was about 120-150L /hr. Mightn't even been that. If you have the right pump like RS said you want need to worry about restricting pressure as the carbs will fill up at the right amount for the floats etc and what evers left will just flow out gently through your return line.

Maybe something similar to this http://www.merlinmotorspo...-PSI/product_info.html

Have a read of this.
 
http://www.racetep.com/webfuelspark.html

Thanks all - i think :-(
I now have 2 pumps that are no good.
ouch!
Thanks for article fordsy - that was helpfull.
A shopping i have to go :-(

I used to use a facet red top I think? with a filter king pressure regulator on the Westfield, you don't need to use a return line with one of those.