im thinking of buying a stock 400ex . is the power
= to that of a 250r? or will i be getting dusted by blasters and warriors?

 

The 400 is definetly = or > than the 250r in regards to power. The only thing the 250r has over the 400 ex is top end. Don't get me wrong the 250r is a nice bike but you must remember it's at least 12 years old or better, making it hard to get parts for not to mention the reliability of a 2 stroke is not as good as a 4 stroke. AS for as being dusted by a Blaster or a warrior, don't worry the only time you'll see them is over your shoulder.