OK, here's what I got so far. Gas cap off, no change. Put vacuum to fuel line from the tank to the pump and it was holding pressure, no gas moving from the tank! That's different than when I did the same test before. Good, seems like progress.
Got out my little compressor and put some air back through the line, re-tested with vacuum and got fuel flowing through the line, like I was able to move an obstruction.
Disconnected the fitting at the carb, put vacuum to the line and was able to watch the fuel fill up the pump and was able to get fuel all the way the carb end of the fuel line.
The fuel level visible in the glass dome on the pump went from almost full back down to about 1/4" in the bottom of the pump when I removed the vacuum pump. I could hear the slightest air leak, I think coming from near the pump.
Running problem remained the same as before.
I wanted to try running from the auxiliary gas can to test the pump but can't figure out how to temporarily connect it up. The pump has female threads but I don't have a fitting that I could attach a rubber fuel line to. I can try the fuel pump pressure test tomorrow.
Just for fun, I opened the petcock valve on the tank to see if any dirt or gunk would come out but nothing at all came out and now the petcock has a small drip!
Regardless, it seems I can easily pull fuel from the tank, through the pump and all the way up to the carb with just a few pounds of pressure on my vacuum pump.
Leaning towards a bad pump but tomorrow's another day!
If I understood all the functions of the pump better it would be easier for me to figure things out!
