How would i make my yamaha blaster 200cc louder?

Not sure why you would want to make your quad louder, but there are a few ways. You can take the muffler off, but it will be so loud you'll either have to wear earplugs (which you probably should be doing anyway) or you won't be able to ride it, it will be so loud. Unless you ride miles from the nearest human being, someone will be bound to call the cops. You could open up the muffler you have and take out all the "inerds." Should look like fibergl insulation. Both of these will hurt performance though. The best method is to buy an aftermarket racing pipe. It'll cost you a few bucks but your quad will be louder and you'll gain a few extra horsepower out of the deal.