Forgive me for this post...
Maybe you should consider the 3hp predator, it has plenty of power for this application and it's smaller too.
The 212 is a knockoff of the Honda GX200. We used to run those in our go karts and they'd do 45mph geared for turns. The karts themselves weight 300lbs, on a tricycle you really have no need for that kind of power unless you are trying to climb mountains. You are going to kill yourself on a 6.5hp tricycle.