Hi NormK,
I've been following this thread and reading your comments. I really appreciate for all the efforts you've done despite you can't hardly walk. I'm just trying to get my head around of what you've done especially to visualise the work without attachment photos. As I've understood, first you have this faulty needle or sticky needle but you haven't tried to fit it with the spring clip you made and instead replaced with new one. Second, you filed the needle crown on a non-working mower for the provision of the spring clip to slide in and the mower runs first pull. We knew it doesn't make sense as the filing of the crown doesn't change the float contact, travel and closing the valve. As you said, it could be a fluke. There are few things that might stick the needle during installation of the primer cap. One is the pressure of your finger holding the float from coming off during installation which pushes the needle harder than the normal voyance compression of the float. One thing you could experiment to reproduce the effect without waiting for the mower to sit for a while is to sacrifice one carburetor fitted with Briggs inline fuel tap on the bottom chamber. Thread the tap into the lowest part of the chamber where the float is setting with flashed inside not to obstruct the float drop. Initially when fuel chamber is full, the float will push the needle close and it likely to stick the needle in. This Briggs fuel tap will allow the chamber fuel to drain to see if the needle will drop with and without the spring clip.
Cheers,
TheCarbyMaster
