First the flooding is likely caused by harden metering diaphragm.
Second on the fuel lines the 2.5mm x 5mm rubber (Echo)is probably the line to go with. Shop sometime will sell line that simply will not fit the carburetor fitting tightly trying to get a good tight tank fit. An alternative is to use tag wire and wrap a couple loops the line at the fitting and tighten. Poor man clamp.
On second trimmer with primer well that primer replacement is at least a starting point.
