I've cleaned out the gas tank on my "new" Pony, replaced the sediment bowl and line to the carb with new stuff and the Marvel Schebler carb leaks gas through unless I turn the gas off at the sediment valve when the tractor is not running. I have had the carb apart and all looks well inside. The needle & seat seem fine. I am going to experiment with minor adjustment in the float level and not opening the valve on the sediment bowl fully, to see if that will solve the problem. Any suggestions? Thanks.