Carburetors just don’t come much simpler than the one you have. There is only one metering jet, and it is not clogged or it wouldn’t run at any speed, or change as you adjust it. The cork float is famous for shrinking and sinking, but yours is working (for now, at least). Some people salvage and reseal the cork float, some make new ones out of a big bottle cork, Myself, I make one by modifying a Nitrophyl Mercury float. Those will last a lot longer than I will.
Your symptoms cry out loud and clear. The tank filter is partially clogged. But you say it isn’t. So I won’t argue the point. You are there and I’m not.
BTW, I only have nine Gale motors. And counting.
