Just take it back.
most of these units are cheap quality off shore built.
You may have to go through two or three to get a good one.
I buy a lot of my parts from advance auto they at least have a good return policy.
The last fuel cutoff valve that I bought from Massey fergy was no better. Time has left us behind
Its go diesel or go home now.
You must have a fuel cutoff that works properly, a fuel leak could burn up you and the tractor.