My 600 will run for a while and then dies until bowl refills with fuel. I get good flow through fuel line but the flow from bottom of carb does not seem to be as strong. My question is how do I measure sufficient flow? this has been covered a zillion times but I did not write down because have never needed before. A little history-bought the 600 at auction. idled fine but not enough fuel to work farm. Ruined Zenith carb seat trying to change and bought a Marvel since I could not find new Zenith seat. Same issue with new carb. I put new fuel tank on because original was rusted through and have put new sediment bowl assembly on new tank. Thanks in advance for helping me with this.