If you ordered Grubee from Kings 3 weeks ago it is not a new 2010 EPA certified motor, is a 2009 or older they had in stock as only gasbike.net is authorized to sell the new 2010's with a 6 month warranty and great phone support.
That means it not only sat on a literally slow boat from China over a year ago, it has sat in a warehouse ever since.
For the most part I have seen and posted about here many a time is the grease dries between the drive shaft and the clutch plate mount shaft sitting that long.
Sure, the clutch plate moves away from the pads, but the shafts are stuck together with dried grease.
Just pop the right side cover plate.
Remove the locking screw and undo the 'flower nut'.
Pushing down on the plate makes this easy.
Then make sure you have the motor drive engaged somehow so the piston won't move and with a lever like a long screwdriver and just use two of three transfer prongs for leverage to break it free.
For the most part I don't get to finding this being a problem until the bike is build and has the chain on.
This kind of stinks as you need to pull the plug and put a wooden dowel or other item that will keep the piston from moving, lift the real wheel, and break it free so the back wheel will move from that leverage turn without the motor moving.
THIS IS ABSOLUTELY CRUCIAL!
Do NOT use that center pin that disengages the clutch plate as a lever fulcrum point!
Look at the last pic closely.
Though close, I am pushing Down on the screwdriver to break the dried grease free using only two of those drive shaft studs and not the center.
Once you get how this works it really is a quick fix.
Just smear in some new real grease
and not motor oil or god forbid WD-40 and you are set to go.
As you adjust the flower nut back on, if you are chained up and clutch adjusted, just tweak it down until you disengage nice with the clutch locked, and engaged when you let it out, and don't forget to put that little screw back to hold the flower nut in place!
A little LockTight here is a good thing too.