Detroit 60 (help)

Where does each pair of those wires go to?

 

Ok You also have a busted bolt at the bottom of that box. If the little ones are the top pair you don't know about chances are they are electrical power to feed that box in some way.

what was the original issue that caused you to take interest in that box? What was the tractor doing getting sick on you. What symptoms?

 

Your filters must be full. The Filters themselves must be there from virgin fresh (I hate to use that combination...) and good quality fuel that never gelled or had enough gunk to gum em up.

Fuel pump problems could be as little as a hole sucking air in via a bad O ring or burned out or whatever.

Im only guessing because I am not physically there to examine. Your thoughts is leading me to educated guesses or final conclusions possible. Mixed with certain things that must be such as fuel filters full, clean and good fuel.

If your poor engine cannot drink when it's THIRSTY it's not going to turn over and work for you.

 

No that thing has nothing to do with your engine sucking air... your fuel lines are not even hooked up to it.

It looks like a fuel heater of some sort.
It's not a primer.

What year series 60? Could just be the check valve on your fuel return line back of the head. If they go bad engine will not hold prime