I also agree. Leave the clutch alone, especially the flower nut!
I'm not clear on exactly what your problem is. "the bike stops at every half turn of the wheel" Is this with the engine not running and with the clutch lever pulled in?
If the clutch is not fully disengaging when you squeeze the handlebar lever the problem is more than likely the clutch cable adjustment. Too much slack. It's common for the cable stop to slip on the cable where it attaches to the clutch actuator arm on the engine. New cables can also stretch initially. Try tightening the cable until there is very little to no slack. Not bow string tight, just enough to take any sag out and report back.
You also said the chain doesn't appear to be "stuck on the sprocket". Nevertheless a loose chain can and will bind or 'bunch up' around the engine drive sprocket. Your chain tension should be set to 1/2" to 3/4" of slack. More than that and it can bind and stop the rear wheel from turning.
Tom
