First off. get this into a new thread which explains the poroblem again, and what you have tried so far and what the resusls were. This thread is way too long and way too confusing.
You say the ped did 42 on a test ride and 30 immediately after you bought it.
Somewhere back in this thread I think I said clean/pull the air cleaner and I think you replied that it was worse at all speeds.
In this post you talk about 15 to 20 when the carb is clogged.
In another thread you are asking for ways to make this ped go faster without changing it. And this on a ped that is not even running right yet.
We are nice guys on this board and try to help everybody but sometimes it is tough.
When you re-post as I sugested above, how about telling us what shape this ped is in, what was it doing before you bought it, was it sitting around or being used. Do you clog the carb because the gas tank is rursty?
Spend a little of your time explaining things to us and we will spend some of ours trying to help you.
End of lecture for today :-)