The male threads at the base of the strainer are 3/8". (They sell a bigger 1/2" version as well) My fuel tank is plastic, so I simply cut off the 1/4" factory fitting, drilled out the hole with a bit slightly under 3/8", inserted the strainer in a socket that fit the nut and forced it to cut 3/8 threads in the plastic tank. (not having a 3/8 NPT tap)
Removed it, put a small O ring on the 3/8" threaded part and screwed it back into the tank. The internal female thread is 1/4", so I screwed a barbed adapter into it with Teflon thread tape, and reconnected the original fuel line with clamp. Been 5 years or so now, no further problems.
Tanks OUGHT to come standard with something like this, as this problem is quite common....AND often misdiagnosed. Seen it many times here on this forum....people go looking for all kinds of filter problems, solenoid problems, pump problems, etc, when the issue is simply lack of fuel flow from the tank.....the first thing to check and the easiest to correct.
My dealer changed my fuel shutoff solenoid twice thinking that was the reason my tractor would die while in use....and the problem was floating tank obstruction...finally noticed just like you...the clear filter bowl would run out of fuel. They pulled the line off (my bowl is located under the tank with about a foot of line between it and the tank), fuel just barely dribbled out....stuck a skinny screwdriver up in the tank and got HOSED with fuel because that moved the bug out of the way that was floating around over the outlet hole. They removed the tank, flushed it and the bug out (some kind of beetle looking critter) into a clean rag, then reinstalled the tank.
That worked UNTIL THE NEXT TIME (out of warranty then). I used an inspection camera with a 3' whip/LED light to look down in the tank this time...and a pair of grabber tongs to remove the wasp that was the problem (tank removal major pain in the backside). THAT's when I decided the tank needed a strainer and went looking for one.
