So we have two scags up at the camp that we use for cutting the grass around the house. Ran fine all last summer, got used a bunch...then sat over the winter. Both of them started right up and we went to cutting. About 40 minutes in, my nephew comes riding down saying it cut off and it's not starting. So we go mess with it a little bit, then I go back to cutting with the other one, until I run out of gas later in the evening. Next morning get fuel in it and after about 30-40 mins of cutting, this one is now doing the same thing as the other one but we are able to get it into the barn. I took apart the fuel pump, it's one of the mechanical type that has a spring/lever that the valve pushes it to operate the pump. I didn't know if you could service the diaphragm part and I took it off realize probably not serviceable but the diaphragm looks in bad shape. So I order a new fuel pump and inline filter and load the first one up to take back home and see if the fuel pump fixes it, then I'll order another fuel pump for the other one.

Fuel pump comes in, put it on and it fires right up first crank, drive it around the yard a bit and all is well. So I go order another fuel pump to take with me for the other one. Get up to the camp and my nephew jumps on to go finish up where we left off all is fine until about 30 mins in, it does the same thing. So I'm thinking maybe some trash in the line or tank, so I throw the other new filter on and that doesn't do anything. So I say screw it and I throw that other new fuel pump on there and still won't start, not getting fuel, can tell no fuel getting pushed thru the pump.

Any thoughts, they are about to get loaded up to take to the dealer but figured someone here might have an thought to try. I never did do anything with the other one yet now.

Fuel filter been replaced? Could be a blockage in the line before the pump could be collapsed fuel line

I would start with the fuel filter too

Scags don't break down.

I’ve changed the fuel filter twice.

I had a exmark get trash in the line where it went from the 90 coming out of the tank to the line. It could be that or like I said collapsed fuel line

souds like ignition coil on the magneto. Ignition coils are bad about working until the get hot. if it wont start at all I would try starter fluid to rule out a weak ingnition.

also I had a zero that only cut off at random times, i did everything you did and it turned out to be the wiring harness connector had dirt in it. cleaned with alchohol

apparently the dirt issue would cutoff the voltage to the carburator cutoff plunger making it look like a fuel problem.

Always the carbs on mine. Here's a trick for ya. Run 40:1 gas in it the last time you cut. Itll keep the carb from sticking. I do that on my mower and a plate tamp at work. I run mixed gas alot in those 2 engines through out the year. The jumping Jack does t like it to well.
It has worked wonders.

How low are you letting the tanks get before refueling? I always try to refill when it gets down 1/4 tank left. Most tanks are going to have some sort of trash in the bottom of the tank. If you let it run all the way out or even close sometimes it will start pulling that trash from the bottom of the tank into the lines and then you’ll have issues. Check all of your lines real good. Pull them off and blow them out if possible.

and only use non-ethanol fuel when you get them back running...

I had the same issue with a snapper pro. About 20 minutes or so into mowing and it would act like like it was running out of gas. Ended up being coil on one of the cylinders.

The fuel lines all seem ok and unblocked, there's really not much fuel line from the tank to the pump. Fuel pump sure seemed like the could be the best explanation for both of them at the same time. We do normally try and use ethanol free gas, but sometimes it's just not available.