My latest idea is to set up a bank of 5/6 carbies polish the primer cap seat with a cotton bud with Autosol on it, fit a new needle and fit a fuel tank above the carbies and leave them with the fuel turned on for a couple of days to see if any leak. At least in doing this I can feel fairly comfortable that when I fit the primer cap and needle to a mower it should not leak. Hard to believe I have to go to all this trouble just because of these stinking float needles. Such a little thing that brings a tough mower to its knees