My yamaha blaster died on me an shows no sign of starting?

I have a 2 stroke 200cc yamaha blaster i was in top gear going full throttle when it started to slow down, the completely died. I checked gas still had some, kicked it turned over and everything but showed no sign of starting. I was for sure it was something big so i tore down top end and piston looked good. I guess i should ALWAYS check small things first. is there a good chance i just fouled the plug?