First of all, this problem has nothing to do with the location of the tell-tale.
I don't know why this was even brought into the conversation.
Secondly, the fact that you hit the key to activate the primer, and you can keep it running, tells me that the carb IDLE circuits are not clean.
There a couple of key places that you need to look....
1. The brass tubes that extend down into the bowl. The center tube is the source of the idle fuel. That tube must be clear. The only way
to be absolutely sure is to run a wire up thru there until it comes out the other side. Use carb cleaner, and a wire to clear that tube.
"What other side?" he says..... Well the other side that exists under the core plug on top of the carb body that you should have already had off....right?
2. In the front of the carb, there is an idle air bleed orifice. #7 in the parts drawing. If you have those clogged up, it will not pull fuel properly.
Unlikely that all three would be stopped up, but something to look at. I have seen them get clogged with fine dust from the foam insulation under the cowling, if you have that stuff.
3. The round gasket that fits around the previously mentioned brass tubes. If that is crushed, torn, otherwise not making a seal, the carb will not draw fuel properly.
4. Under the plate on top of the carb you will find very tiny holes drilled and opening up into the venturi . Those holes must be clear.
