The 5220 is a diesel. So you mean the ejector pump not carburetor right?... When my 1520 cut out I usually had to bleed the injectors to restart. I had a faulty fuel transfer pump. You might have the same problem.... FB.Venting was okay and fuel drained clear from tank drain. Tractor ran okay for light jobs for about a week. But when I run machinery at a high PTO it runs in spurts and eventually will just cut off. I did not know if I should start with the fuel lines first or maybe the problem could be in the carburetor or jets.