Mercruiser fuel leak

[Cyberosmos]

Hi!
I've been trying to figure this out as well as search for the topic.
I have a rather massive fuel leak where the fuel line meets the carburator.
My engine is a mercruiser 3.0 from -98.
The strange thing is it hasn't leaked before.
I can't seem to remember if there should be any gasket here.
There are no gaskets as far as I can tell now, just the spring and the little filter.
It seems like there is no problem with the threads as far as I can see. I have the feeling there is some part missing here, as I took the boat out the gas started dripping from the fuel line as well as gathering under the carburator, and also dripping from there.
From what I can gather it seems it leaks from the threads or where the big screw meets the carburator, but not sure as I all gets pretty immersed in fuel.
From what I can tell I can screw them both all the way in so I can't grasp why there is a leak.
Somebody here that could help me out?

 

[Alumarine]

There's supposed to be a gasket that fits around the threads of the large nut.

 

[87 criscraft]

I'm pretty sure that there is a gasket,kind of a metal ring,that goes the carb and the big fitting

 

[Cyberosmos]

Thank you both!
Is there one metal ring or is it two?
I guess one goes "into the carburator", should there be one also between the filter and the nut?

Looks like there should be 2:

 

[Alumarine]

I would assemble them like it is shown in the picture you enclosed.

 

[Cyberosmos]

Thanks!
Yes, it's clear, one metal ring, and one gasket inside the big nut.