engine locked up

[Jackshuge]

I have a pretty big problem with one of my 2 stroke 80cc engine. I have used this engine in the past quite a bit, but i now recently put it on different bike i got it running for a few minutes but it wouldn't idle. I then noticed that the carb was leaking gas from the air intake even when the engine was off i thought that was odd but i tread to start the engine again but it was completely seized up. i have tried turning it over but the thing wont budge. I took the head off and there seems to be no scaring on the cylinder. does anyone have any solutions or reasons for this problem?
I currently have the the cylinder soaking in WD-40
I don't think it was the gas i was running it 40:1 tho the oil could be expired but i've ran oil like that all the time.

 

[darwin]

I'm almost entirely Western European in my genetics, so getting my Polish on is just a way to claim the 3% of me that is Eastern European.

Yea, I'm a Mutt too.