There is something more wrong with this than the carb's jet, needle and idle. It never does the same thing twice. Still wants to start with the choke closed but lets put all that aside for a moment. What would cause a small rev (with the clutch held in) to come back down, but a large rev to behave like the throttle is stuck when the throttle isn't stuck? The first two times it happened I hit the kill switch and it shut right off. The third time it happened the kill switch didn't work and the engine was screaming! I had to let the clutch fly to kill the engine. All of this happened after adjusting the idle so that it would run with the clutch held in.
This thing makes no sense whatsoever.
This thing makes no sense whatsoever.