The karts look pretty crap really, they have rollcages which proper karts don't have. It says nothing about the engine but I would expect it to be a 4-stroke thing giving 6-7hp. Won't quite do 45mph I don't think.
Tips to be fast: be smooth. Take the racing line (outside then to apex then back to outside). Don't go flying into a corner just to have to slow down tons to be able to get out of it, slow in, fast out. Oh, and be smooth.
EDIT: Ignore my engine part, I didn't see they were electric. As Stu said, glorified theme-park karts. Search on google for 'karting tampa bay' and i'm sure you'll find something a bit better