Description: I have a Hollay 12-125 Elec Fuel Pump that is BLASting FUEL to the carb. it's nice to know that I won't have fuel delivery trouble, but I need to lower the pressure so that it doesn't blow the floats off the carb! This fuel pump has the regulator built-in & can be adjusted. The only problem is that I get no response when adjusting the screw on the pump!!!


QUESTIONS: Why is the pressure not adjusting? Have I somehow damaged the setup? I don't think I did, but who knows. Also, the Adjuster screw has never really seemd like it would secure well, what are your thoughts?

Buy a Holley regulator. Its a good idea anyway.

this is a good idea because: you can run 12-15PSI up to the carb to ensure you have enough fuel delivered to the engine, then step it down right at the carb to the desired 7-9 PSI. I'm afraid that if you stepped the pressure down at the pump with the internal regulator on it, that you'll also be cutting back on fuel delivery.

I'd do that, but this pump has the regulator built-in. As such, the fuel pressure is adjustable & it doesn't need an extra one.

I'm waiting for the people @ Holley to come back from vacation so that they get to reacquaint themselves to the workplace by answering my questions.

After reading the instructions it just sounds like it has a preset internal regulator, it says nothing about it being adjustable. It sounds like you're tooling around with the non-adjustable relief valve...

What's the pressure you're getting?

I'm looking again @ the Holley tech info & although it is preset, it does refer to adjusting the pressure.

However, the screw I'm turning does nothing to the pressure, up or down. Maybe it is a Press. relief valve like you say, but there is no other adjustment screw that I can see. Now I'm really confused!

Gotta wait for Holley to return from vacation.

The manual is both for a 12-125 or 12-150, the 150 comes with an EXTERNAL regulator that is adjustable. That is what they're talking about, your 125 is non-adjustable.

Seems so. I don't have a fuel psi guage, but whatever the pressure, it's much more than needed. And, from the looks, it's more than the 6psi it's supposedly set to. But, won't know until I get a guage.
Thanks.

Well what makes you think it's too much? Get a gauge on it before blaming the pump...