The one in the bottom right of that picture is the varmint in question and the one I ment, sorry I should have been clearer, it stops the needle from sticking shut.
Ha! Thanks Hilly. Pity you are so far away. You have all the right info.
The spring is still in that carb you got off eBay, maybe it will become obvious when you get to look at it? Hope so anyway lol
You are past my Bendix know how, I will be following along in learning mode 😁
One thing I did see was that there is an oring around the main jet that can/does perish and fuel can then get past making the mixture rich, maybe that could be part of your sooty plugs scenario if you haven't been there yet?