Good question and one that will tell you if it is a chain bind problem or if the clutch cable isn't adjusted correctly. If the cable is too loose the clutch is staying engaged even with the handlebar lever squeezed.
New motors come out of the box with the clutch 'stuck"
Hey Tom, The guy says its turning, Just real clunky. Sounds to me more like something aint lined up right or the wrong size chain. I've had chain that fits one drive sprocket just fine, But just wants to chunk and clunk on another. I blame it on the difference's between the 10 or so manufacturers.
If this doesn't work then clamp the flange in a vice and 'cold bend' the pipe. There is no reason to heat it. The pipe will bend without heat but you need to take it easy and go slow so you don't over bend it. However, enlarging the holes will usually give you the clearance you need. Good luck.
With that cover removed the clutch will be engaged. The sprocket won't turn easily unless you remove the spark plug. That cover is part of the clutch actuating system. The cam inside it pushes against a steel pin, called a 'bucking bar' which in turn presses against a ball bearing that rides against another moving part inside that when moved releases the spring pressure and disengages the clutch. If that cover is not on and the cable not installed it will be difficult to rotate the drive sprocket and if the chain is installed the rear wheel won't turn easily.
