My GZ 's top speed seems low

[paulisnofun]

I don't have a history on the bike, but incan ask the guy I bought it from a few questions.
I took the filter out, and banged it around a bit and shook out any debris that was in there. I am going to pick up some some seafoam and dump it on the gas tank. I am also going to try to research a little more about vacuum leaks, and how to find them.