I've never done this with two strokes, but when messing with an old engine I usually get good gas, check spark, then spray some carb cleaner in the carb to get it running. It works like ether but helps clean the carb, but don't use too much you'll need up the engine. I'll also run some seafoam in fuel too. I hope this helps. Good luck.
First things first. Redo gas tank. And post pics of the fab work. That engine is sitting very high. Center of gravity will be heavily effective.
That gas tank has to go.
The first thing you do is check for spark.