Originally Posted by Downhilldai
As Nos says, whip the plugs out and turn the crank/flywheel by hand.
If you remove the valve cover, you can check the valve clearances when the valves appear to be fully closed. If there's excessive clearance, then the valves are likely to be stuck open.
If this is the case then you may be able to free them off by applying some releasing oil on the stems/guides and continue turning the flywheel by hand to work them free.
This sounds like a good idea. It appeared that the valves were opening and closing. At least it looked that way from. where I was standing.
Perhaps I should take a HD video of the valves and you could tell me. (?)
I'm thinking this thing may have jumped time in a big way. If I turn it by hand it will only turn so far before it stops me. But if/when I hit the key it rotates fine.