I have a 2001 grasshopper 721 Kubota gass. It has around 480 hrs on it. The other day wile mowing it dies like it ran out of gas. Fuel filter was empty took the line off and manual pump wasn't pumping. Removed pump and could get it to pump. Installed it back waited and it fired up. Yesterday while mowing I was almost done mowing (45mins) it did the same thing. I let it set for about 3 hours and it fired right back up. I'm thinking it's the fuel pump. Has anyone had a similar problem?