John Deere E120 Wont start

[KENGOLDING]

2.5 hours on the mower.

Starts fine with a burst of starting fluid

remove the small plastic inline fuel filter and nothing comes out, other than a small trickle

the tank is almost full.

Is there another filter?

 

[bertsmobile1]

Welcome
The main jet is around the size of 3 hairs so just a trickle from a 1/4 " tube is a lot for a 1/ 64" hole.
As it is brand you should take it back to the dealer rather than messing with it and risking them voiding your warranty.
If the engine will not start without starting fluid then chances are the choke is not fully closing so that is the first thing to check
If it does not fully close loosen the throttle cable clamp and move the cable ensuring that you have the throttle control in the choke position.
If you want to persist then we need to know where you disconnected the fuel line.
The fuel tank is under the seat so there is next to no height difference to get a good pressure head.
The fuel pump has a check valve on it so the gravity flow from the carb side of it will be substantially less than the gravity flow from the input line
When testing the fuel flow do it with & without the fuel cap on.
If there is a substantial difference between the teo then the tank vent may be clogged
Let us know how you get on.