Please help a newb. Weber fuel pressure regulator

[texas_ag]

Please forgive my ignorance... Can someone please tell me how to adjust this weber fuel pressure regulator? There were no instructions whatsoever on the "instruction" sheet.
http://classicinlines.com/proddetail.as ... FPR&cat=51
There are 2 nuts on one side (one is a cap nut), and a larger bolt on the other side. I don't want to start taking stuff apart without knowing.

Also, how do I verify the pressure setting? Do I need to get a fuel pressure gauge? I don't see any reference marks anywhere...

sigh.

Thanks.

 

[rbohm]

8) according to the product details, it comes preset at 3psi. i suggest contacting azcoupe and ask him to send you the instructions that come with the regulator.

 

[texas_ag]

It came with an instruction sheet, but it doesn't explain how to adjust it. It only lists the specs and a couple of pictures. It's useless.

 

[1966_l6]

Is it necessary to have fuel pressure regulator with weber ?

 

[ausxb]

From Memory the acorn nut on top is the adjuster with a locknut under it, you simply onlock the locknut and adjust the pressure with the acorn nut.
You will need to tap into the fuel line between the regulator and carb with a pressure gauge and adjust to the pressure you require.
Hope this helps.

 

[67drewstang]

Is it necessary to have fuel pressure regulator with weber ?

Only if you want to run it with the mechanical pump. If you buy a Weber electric pump, it automatically delivers fuel at sufficient pressure.

The reason why there aren't instructions on how to adjust it, is that it isn't meant to be adjusted by the user. As long as fuel is delivered at a constant pressure, the carb should function.

I'm curious as to why the OP wants to mess with fuel pressure.

Drew

 

[texas_ag]

Thanks for the tip aus.
Drew, basically it's because I don't trust it and wanted to verify the setting. I wasn't sure if I removed one of the bolts/nuts if I would see an indicator telling me what it was set to, or if I would mess it up. I'll install as-is and if I run into problems I will verify with a gauge. It's supposedly adjustable from 1.5 to 20 psi.
Thanks again.

 

[1966_l6]

Is it necessary to have fuel pressure regulator with weber ?

Only if you want to run it with the mechanical pump. If you buy a Weber electric pump, it automatically delivers fuel at sufficient pressure.

The reason why there aren't instructions on how to adjust it, is that it isn't meant to be adjusted by the user. As long as fuel is delivered at a constant pressure, the carb should function.

I'm curious as to why the OP wants to mess with fuel pressure.

Drew

Thanks Drew
What is the good pressure for mechanical pump ?

 

[powerband]

The mechanical pump pressure is RPM related, that's the problem ... As the RPM goes up so does the pump pressure, a regulator can prevent the unseating of the float needle with too much pressure and normal engine vibes'.

An economical Fuel Pressure/Vacuum gauge can help sort out many pesky tuning problems. With a TEE in the line you can see the mech. pump fuel pressure changes with the engine running. Used as Vacuum gauge can show bad valves, leaky intake and help tuning for power and economy.

common dial-type FP regulator on my '63 later ruptured pumping gas all over engine > :thumbdown: < :
.

 

[67drewstang]

Thanks for the tip aus.
Drew, basically it's because I don't trust it and wanted to verify the setting. I wasn't sure if I removed one of the bolts/nuts if I would see an indicator telling me what it was set to, or if I would mess it up. I'll install as-is and if I run into problems I will verify with a gauge. It's supposedly adjustable from 1.5 to 20 psi.
Thanks again.

I see. I don't want to sound flip, but I dealt with an aircraft owner once who had an obstructed/too small fuel line that wanted to increase the pressure instead of dealing with the root problem. Just wanted to be cautious, but you obviously aren't thinking in that direction.

Just looking at the outside housing, I'd say the prior description on how to adjust is accurate. It looks like there should be some kind of spring loaded valve/tappet that can be screwed tighter or looser to adjust for pressure. Frankly, it reminds me of a gas pressure regulator like you see on propane tanks, from the outside. Testing those should be a cinch from the outside, using a calibrated presssure source.

Drew

 

[Explorer]

Is it necessary to have fuel pressure regulator with weber ?

In my experience, yes. Weber carbs do not like over 3psi fuel pressure. This is why the regulator is included when buying a Weber carb kit.

 

[1966_l6]

Is it necessary to have fuel pressure regulator with weber ?

In my experience, yes. Weber carbs do not like over 3psi fuel pressure. This is why the regulator is included when buying a Weber carb kit.

Thanks
I 'll buy fuel pressure regulator

 

[MT63AFX]

Is it necessary to have fuel pressure regulator with weber ?

In my experience, yes. Weber carbs do not like over 3psi fuel pressure. This is why the regulator is included when buying a Weber carb kit.

My recent experience and research, with my Weber 38 is using the Viton needle-seat and bypassing the regulator altogether. Previous owner had the OE-style mechanical FP connected through the regulator. I have an electric Carter pushing around 8psi at the gauge and the mechanical FP in a drawer, RodC.