The other day I went down to start my 2008 Yz450f and it had no compression when i tried to find tdc to start it. I was able to continually cycle the engine easily by hand, that is how little comp it had. The weird thing on this is that it ran mint and crisp two weeks before and had not been touched since. (started in one to two kicks, great throttle response.) Any Ideas on what this could be before i start tearing the engine apart to find the problem?