well the yzf are sport bike i.e. yzf600r and the yz###f would be a four stroke motocross bike i.e. yz250f, mabey the yzf250f is a 250 sport bike??? but most likely a typo!
That has to be a typo, I never heard of yzf250f. yz250f is a four stroke engine yz250 is a two stroke. The 2 stroke is a more powerful bike out of the box, mainly used for motocross. yz250f is used for everything from supermoto to supercross as well for trail riding.