SOLVED!!!

I have found the culprit. It is really dumb but I think it may benefit another YS inexperienced person so here goes...

The mistakes started early...

When I was fitting the fuel lines for the first time, I think I swapped them... so for those inexperienced, do use different color fuel lines for this one. In most cases, this wouldn't cause too much trouble... But in this case I think that some how the fuel and pressure somehow blew the tube with the clunk out of the tube. I've never heard of this happening before but I am just telling it like it is...

This explains why the engine was always temperamental as the gas sloshed around the tank, air bubbles would be sucked into the fuel lines to the carb. This would then cause the engine to go from rich to lean to rich to lean and the only way for me to keep it running was to make the rich rich enough so that engine rpms were high enough to pull in another bit of fuel. But as the fuel level went down, the gaps kept getting longer and soon the engine was running so lean that it detonated so violently it ruining two of my spinners.

Lesson learned? Honestly, I'm not sure... I guess don't connect it up incorrectly and be absolutely sure that the fuel pickup in the tank never slips from the aluminum tube?