ORIGINAL: JohnBuckner
On board glow is a band aid that will not help and only make things worse. An inverted engine in most cubs is a bad idea, real bad The simple fact is you will not be able to lower the tank enough in that small nose to prevent hydro locks, syphoning and excessively rich low range mixtures. In Cubs the only orientation that works well is sideways and thats why almost all you see will have a sideways engine.
In the pictures you have virtually no inlet air and not much outlet either of course its getting hot and quiting.
You said you set the 'needles' are you aware the K&B Sportster .65 does not have a second low range needle but instead has that brass serrated disc that rotates the jet just slightly within the venturi throat to control the low range mixture.
Reread the instructions for your engine or better yet get someone experianced with the old Sportster series engines to help.
I do know how to adjust the engine and I am aware of where the low range adjustment is. I did a lot of reading on this engine so I knew how to adjust it before I even started it up the first time.
You're right that I didn't have a large enough air inlet hole and that has since been fixed. The reason I didn't have it larger from the beginning is that there's not a lot of space on the front of the cowling to cut a hole.
Well, I'm off to give it another shot.