I see you were wanting a pipe anyways, get the pipe, remove your airbox lid, make sure you got a good clean air filter, and jet the carb after putting on the pipe and the other, thats a good start. Also, make sure your running good gas, I run 91 octane (all thats available here), no ethanol.
Besides the pipe, jets are only $3, and filter might just need cleaned, other than that, a little time and hopefully that will help you out some. Put a fresh plug in too, its only $2, and then you know thats not holding you back at all.
What size tires you have, and do you have stock gearing? (count the number of teeth on the sprockets were the chain is if your not sure)
Does it feel like its reaching top RPMs in top gear, or only running halfway?
Does the blaster seem to run great, or is it boggy, or surging at all?
Hopefully that helps a little.