Clutch too tight or not tight enough

[stangkid]

I've been working on this bike for 3 weeks, and I am on the brink of giving up. I have had to order a new tensioner, a new sprocket, everything has seemed to gone wrong. I have gotten to the final stages, and the tensioner wheel snapped so I ordered a better one. Now, the clutch is either so tight that even taking off the spark plug, I can't turn the small gear on the engine, without any compression. If I loosen it even 1/8 of a turn, the engine will never engage.

Should I just order a new engine?

 

[Ollie]

Have you taken the clutch cover off to see if the clutch is properly engaging/disengaging? Also, when you say you can't turn the small gear on the engine, do you mean by hand or when the chain is attached to a wheel and you're trying to roll it along? Both my engines were really stiff at first, but after pedaling forcibly for a while I was able to move it by hand (with the clutch disengaged).