Moped Army

I am new to modifying. gotta start somewhere. Wondering if anyone has any good suggestions for my kreidler. I'm not looking for a TON of speed, i would like to go 40. Whats the fastest way to get there? What exhaust do you recommend? I saw something about using a rubber tube to cut and modify the intake....does this have any negative effects?

Not much on Kreidlers on here....I never did like anything easy.

If you know a friend with a modified Kreidler, give me contacts...anything...