RE: eratic performance
Hi
I t is little doubt that this engine has been running lean at some point, from the color of the engine it looks like it has been very hot at some point.
I would also have shortened the yellow fuel line so it doesnt go so high out from the firewall, it looks ok the fuel line install but...
Also if the engine has been very hot, i would also check the head bolts to make sure they are not loose.