Harely Davidson motorcyles used a gravity feed fuel setup prior to 2006 when fuel injection was first introduced.
HD setup uses a 1/4 turn shut off petcock valve with an integrated filter screen that protrudes up into the fuel tank.
The filter screen is cylindrical and fits up through the fitting in the bottom of the fuel tank.
These petcock valves are trouble free and very reliable. There is no glass material.
The HD style petcock shut off valve uses an 3/8" NPT male thread.
Aftermaket petcock valve with filter screen can be had at many motorcycle suppliers.
JP cycles in Anamosa Iowa is one of the best suppliers.
Looking in the JP catalog there are many selections for this style of shut off valve.
The least expensive is $15.
The output connection is a rubber hose barb fitting.
My tractor is totally torn down from the bell housing forward. Will be replacing the glass sediment bowl setup with an HD style shut off valve.
This will be an upgrade in design, but not authentic, however.
The HD engine displacement is 91 CID compared to N engine at 120CID.
Find no problem with flow rate capacity.