It's pretty unlikely that your motor is completely dead.
The reason you can hear the engine with the spark plug out is that there is no compression when the spark plug is out, so it flows relatively smoothly - this is how I know that your piston isn't stuck in the cylinder.
Now, when you try tomorrow to unstick the pucks (if that's what's wrong), you want to be sure that your clutch is adjusted properly.
In the picture above, you can see the drive sprocket and a pin in the center of it where the green arrow is pointing. If you look at the cover you take off, there is a camshaft in there - it's basically a rod with a flat spot. You want that flattened spot to be perfectly flat against the pin. This will maximize the amount that you are able to move the clutch when you pull the lever. How you do that is pretty simple - with the cover off, take a look at the camshaft (the one with the flat spot) and using the lever on top, line it up to where it would be flat against that pin. Now, you just basically have to remember where the lever is positioned, and tighten your clutch cable to where the lever is in the same spot.
After that, you really don't want to adjust that cable anymore - cause like I said a bit ago, that's the spot where you'll get the most clutch movement with your lever.
I gotta head out in a couple minutes, but I'll post again and mention how to adjust the clutch plate a little bit later.
ADDITION:
Looks like things are delayed for me here, so I can tell you how to adjust the clutch plate.
To start - push the clutch lever in and lock it. On the right side of the motor is a cover with 5 bolts, so you'll need to remove that. Underneath it, you'll see two geared wheels - the largest one is the one we're going to working on. At the center of it is a flower nut, with what looks like metal petals on the outside of it. There is going to be a locking screw between two of the "petals", so you'll want to remove that first. Now you can freely move the flower nut - when you tighten it, it brings the clutch plate closer to the clutch pads/pucks, and when you loosen it it brings the clutch plate away from the pads/pucks. Your goal is to have the clutch plate off of the pucks enough so that the bike rolls freely when the clutch is locked, but when the clutch is not being held in you don't want to be able to roll it freely at all. Generally, I say that when you're adjusting it, you want to be able to test it by firing up the bike, and holding the back wheel off the ground with the clutch locked. If the wheel moves, you know the clutch plate is too tight. But in your situation, you haven't fired up the bike yet, so you're just wanting to make sure that when the clutch is locked, the bike rolls freely, and when the clutch lever isn't being pulled you can't roll it.
