Engine Seized?

Got an old parts bike that I am thinking of rebuilding. It doesn't start (didn't when I got it) and I am slowly taking everything off of it to get down to the frame. I have found that I can't turn the crankshaft (at the ignition) at all. Is this because I drained all of the oil out of it? Does it mean the engine is seized? What does "seizing" mean?

Help me out here folks. Thanks.

 

the most common "seizure" is one or more pistons seizing up (getting stuck) in the cylinder due to a ring failure or other internal catastrophe.

A plain-bearing motor can also seize up at the main bearings if there was a complete lubrication failure.

If the motor sat for a long time, there could be enough rust inside the cylinders to prevent you from easily turning the motor over. Having the oil drained out, while not a good thing, isn't going to keep the motor from turning over unless it sat that way for years.

Are you sure it's not just stuck in gear? If it's in gear, you won't have enough "oomph" to turn the crank by hand.

You could shoot some Kroil into the cylinders and wait a few hours then see what happens...

 

You'll want to keep it together so you can use the rear wheel to try and bump it free if possible. As Fitz said, pull the plugs and shoot some Aero-Kroil in the cylinders. Let it sit. Then with it in 5th gear try and move the rear wheel back and forth until the motor turns. Once it does you'll be able to pull it apart and slide the cylinders off the pistons.

 

HEAD SLAP! It's probably in gear! I will check it out. Thanks guys.