Hello everyone. I have a good friend with a 1969 Case 730. He ran it empty of fuel 2 weeks ago. Once he refueled the tractor, and primed it, it started and ran well. He was able to use the tractor for 2 hours. While driving, it began to struggle to run and stalled. He says it will fire up and high idle, but only for less than a minute, and it stalls again. We are wondering if he picked up some junk from the bottom of the tank, when he ran it empty. I am mechanical, but have never worked on a tractor. I see what looks like 3 fuel filters. The first two(lower on the engine) are actually painted the engine color. The third(higher and closest to the fuel pump) is not painted. Would you recommend changing 1 or more of the filters? Any direction would be appreciated. Thank you. If it helps, he believes it is a CK model.