Thanks for the reply Roger. No problem...
(I can't see the threads in the carb, maybe with a dental mirror and light, however I'm back home and it's at my ranch 25 miles away.)
I went out and looked at my 202 this morning, and I can see why. Very hard to see with the loader frame in the way... So, I looked at my 8N, similar carbs, different models, but same high speed needle adjustment.
(The brass threads on the needle look fine except for maybe 1-2 threads about halfway down, which I assumed is where the end of the spring was wearing on it.)
Looks can be deceiving!! The needle threads should be clean and sharp. That is a brass needle and should wear before the carb body does. The wear might possibly be from where the washer and gasket has worn it.
(There must be more thread than that in the carb body? Are those threads cast iron?)
Yes and yes.. The cast carb top is drilled and tapped for the needle and appear to be at least 1/4" or more deep into the casting.
(I could feel the threads skipping over (like running a comb over a table edge) when I tried pushing the needle back in, I just can't imagine they went from OK to that without any hint of binding or trouble coming out.)
That's not good. Like I said, inspect the needle threads closely, if it feels like a comb going over a table edge, chances are, they've flattened out, not hard to do with a brass screw. Probably been wearing a long time, depends on how much adjusting has been done in the past.
(No evidence of thread material from the carb on the needle threads.)
That is good, but being that the carb body is cast, the needle should wear first anyway.
Paul, I don't want to be misleading, all this info is based on your carb being the Marvel-Schebler TSX series. I looked at my carb, and my 202 parts manual. If you have a different carb, like the Carter that was also used, then things will be a bit different. My suggestion is that you go ahead and pull your carb so it's easier to look at / work on. If it is the M.S. Carb, then this site sells the major rebuild kit for it that comes with a new high speed needle, gaskets, bushings, etc...
Good luck and let me know what you find out...