With the belt removed the driven clutch should close much tighter. Also, and this is important, when the belt is off the outside sheave of the clutch should have a rotation tension also. If you turn the outside sheave clockwise, it should spring back counter clockwise with a snap.
When you take it apart to clean it you have to wind the spring a little bit. You just need to wind it far enough theat the buttons will stay in contact with the three towers. perhaps 120 degrees of rotation when you put it back together.
The way yours is in the pictures your minibike will have good top end but really slow out of the hole. Correct the driven and you will notice a big improvement in acceleration and low speed riding.
Your belt should be loose but now where near as loose as shown.
Danford1
