Hi CM,
excellent explanation and proof the other aftermarket stuff is junk as I have said many times some years ago. I started on this problem a year or so behind you and I was turning down needles to try and get them to work. I couldn't find a viton one I thought I could work with so I was pulling out the seat in the primer cap and fitting a Briggs seat in there and turning down the Briggs needle to suit. I had moderate success and I guess there is a few still floating around that I haven't seen again. Any that I have come across I have replaced with a cap and needle you supplied. Hopefully you still have stock of the needles as once I get back to fixing mowers again I will need more, although my supply of mowers over the last 12 months certainly has dried up
