Re: CARBS...I give up
"Lowered the needle slide one notch down". Do you mean you moved the C clip one notch up? This would aggravate your problem. I think it's an air leak.
Some of these carbs come with an idle screw that isn't long enough, no matter how far you turn it in, it won't idle.
Youi said the engine either races or dies, that's an air leak.
Also, putting silicone on your head gasket is bad news.
I would remove that and replace the head gasket with no sealer of any kind. A leaking head gasket will generally show itself as a mess on the engine, and loss of power, not as the symptoms you've described. A leaking base gasket will act the same as an air leak, partly because it is.