It would have nice to continue on your last thread so we remember what lies we told you in the past :) So, I'm confused. You should have a metal fuel line coupled with a short piece of fuel line on either end running between the carburetor and the fuel pump- correct? Rearward from the pump you should have a short hose to the fuel filter and the fuel line that runs from that filter to the pick up tube on the top of the fuel tank- also correct?

There is no pressure or flow to speak of when the rider is not running. A properly working mechanical fuel pump though is capable of collapsing a fuel tank if the fuel cap is tight and vent plugged, so they work well when the machine is running. When the engine is not running, the check valves in the pump relax. If you emptied the filter, the line from the front of the filter, drained the float bowl of the carburetor and cranked the engine- it would take about 10 seconds for the engine to start. Use that as a reference point. Imagine if the pick up tube in the fuel tank is leaking part way up. That could be reasoning for a better start with a full tank. At times, this can cause a stall. You would need to remove the fuel tank to know.

If you feel there is a leak and there is nothing at an external point, the pump could be leaking internally. Straight line chalk is real pretty and might help. On that note, is the oil level staying exactly the same when checked cold from day to day and is the any fuel presents detected in the oil? The carburetor can also be leaking. If it were to leak past the float valve after shut down, it would only do so to to a certain point- maybe just enough to drain the metal line. But the bowl should remain close to full. To verify this, remove the air box.

At this point, you could try a few things. You could drop 2 feet of fuel line into a supply can from the pump and see if the extended crank is still there. You could slightly raise the float level. This could carefully be done resting the tang of the float on a small screwdriver so you don't damage the tip of the valve. The float is technically non adjustable BTW. Or, you could replace the float valve.

Donuts if I guessed right anywhere in there....

OP: I replaced the filter and the 4" rubber tube the connects it to the carburetor, That was a week ago during which the tractor sat in the shed in the yard. The hose was the original on an 18 year old tractor.

After a week the yard needed mowing again, so I mowed the yard yesterday evening.

GOOD NEWS, when I checked the oil, I noted the gas level in the filter was where it should be, and when I tried to start the tractor it turned over twice and started on the third revolution. So it appears that the problem was a small leak either in the old filter or in the 4" hose.

If you are having problem started you may consider this approach to fixing the problem.

Sounds like flow was restricted to me and you got rid of it by changing out the filter and tubing.

I would agree with sax,s conclusion and the adding of additional fuel within the fuel tank would create additional "head" that may have overcame the restriction and allowed the Engine to fire quicker initially prior to replacing the fuel line and filter .