I have an older Bob-cat T3100 that I haven't had out in a while. Now that I've gotten it out and have an interested buyer it is having problems with fuel delivery problems I believe. The fuel filter will rarely stay full. It will run alright for a while then it will slowly run out of fuel. You can stop let it catch back up and it will be fine for a minute or two. Is there a type of cam or something that runs the fuel pump that may be worn? Or could this possibly be a carb problem? I am unsure and would lke to get this sold. Thank You for any advice.