spark plug removed

Hello. I'm running a two stroke 80cc engine, and until recently, I've been enjoying the rides. The clutch just stopped freeing the wheel, and I tightened up the clutch cable. No good. I did find that it will only roll freely with the spark plug removed, so I don't think its seized. I don't...

My boyfriend ordered a RAW Silver 80cc bike engine from rawmotors.com, and they were kind enough to not include an instruction manual. We've managed to put it together via several Youtube videos, but now that we've got it put together, the back tire refuses to turn. And yes, we are using the...