Need help - unknown elbow on Carb MA-4-5

[pilot-as14]

Hello, 

There is an elbow on the carb, which is not present on any drawing of MA-4-5. Is it correct, or has the previous owner tinkered it?

Thank you!

[Rwsavory]

My carb has an elbow fitting there. 

[pilot-as14]

could it be intended for excess fuel?

[47U]

25 minutes ago, pilot-as14 said:

There is an elbow on the carb, which is not present on any drawing of MA-4-5.

I believe that is the fitting for the -2 hose through the firewall to the fuel pressure gauge.

 

[Rwsavory]

It might be for your fuel pressure gauge. I’m not a mechanic, however. That’s a pretty crusty looking carburetor. Here’s a picture of one in this thread. 

 

[pilot-as14]

yes, yes, the whole plane was junk. But I'll fix the carburetor. 

[pilot-as14]

On 1/17/2024 at 6:40 PM, Rwsavory said:

My carb has an elbow fitting there. 

As I understand it, this is not an AN fitting. But what type is it?

[Rwsavory]

https://www.aircraftspruce.com/menus/ha/an_elbow.html

[pilot-as14]

On 1/17/2024 at 6:53 PM, Rwsavory said:

It might be for your fuel pressure gauge. I’m not a mechanic, however. That’s a pretty crusty looking carburetor. Here’s a picture of one in this thread. 

 

 

On 1/17/2024 at 6:40 PM, Rwsavory said:

My carb has an elbow fitting there. 

 

[takair]

Fuel pressure gauge take off.  The “B” nut still has the hose fitting attached, but the hose is missing, that’s why that looks odd.  The pipe fitting may be someone’s local modification to restrict flow to the pressure gauge, this is somewhat normal practice.  Basically a rivet driven into the fitting, peened and drilled.  I just made a few of these for my own experimental project.

[pilot-as14]

11 minutes ago, takair said:

Fuel pressure gauge take off.  The “B” nut still has the hose fitting attached, but the hose is missing, that’s why that looks odd.  The pipe fitting may be someone’s local modification to restrict flow to the pressure gauge, this is somewhat normal practice.  Basically a rivet driven into the fitting, peened and drilled.  I just made a few of these for my own experimental project.

thanks for the reply!

[Jsno]

That is a restrictor.  It keeps the pressure gauge from fluctuating from pulsating action from the fuel pump.