uhh, don't totally remove the muffler. a straightpipe is not good for a 2 stroke.
you can modify the stock muffler for good flow, and it will be a little louder than stock.
if you can take your muffler apart (some are screwed together, some are welded). remove the muffler end cap.
remove the catelitic device that's inside the muffler, all the way up at the top where the pipe goes into the muffler. (it's a small round peice of steel tube that's about the same diameter as the muffler and it has corrugated steel coiled up inside of it. if your muffler is screwed together, there will be one external screw holding this peice inside the muffler, and 2 external screws holding the end cap on.) Drill 1-2 small holes in the baffle plate (not the baffle pipe) that is welded to the inside of the muffler end cap.
i have done this to 2 different stock mufflers and they work great.
of corse, the BEST thing to do is chuck the stock pipe and muffler and get an expansion chamber with a muffler on it. a modified stock muffler works well on an expansion chamber, but it may not fit on some expansion chambers due to the way they are built and where the end of the pipe ends up.
I am using a spookytooth exp. chamber with a modified stock muffler on one of my bikes and it made a big difference in performance.