The only way to get your blaster to sound like a yz250 is to put a yz250 pipe and motor in it. Anyone with a trained ear can tell the difference between a quad and atv. Aftermarket pipes will give a you a sound closer to what you are trying to achieve though. There is a thread on here somewhere with clips of all the pipes for blasters and how they sound. Aftermarket pipes are louder typically because the stock pipe is very restrictive but they all also have their inserts and things that keep them under a specific dB rating. But for someone that doesn't need to stay under a dB limit, you can remove these inserts if desired.