Diaphragm shouldn't turn around the slide easily. If the diaphragm is distorted could cause this and problems your having? Diaphragm and slide comes as an assembly and isn't cheap! About $86 new. OPT

 

*****SOLVED*****

Put in the new diaphragm/slide assembly and the low end throttle response was a bit better, but still wasn't much improvement.

Was about to give up, then looked at the slide needle again. The E-clip was on the lowest position. I moved it to the middle, and it ran different instantly. It revved much faster and higher, and now it spins the tires!

I wasn't expecting it to be quite as fast as it is now! I don't really miss my YFZ any more...

 

Sometimes it's just the simple things that are easily overlooked. Now you can help others with carb problems. Good luck OPT