News flash ! ! !
Person riding a motorized tricycle crashes while trying to negotiate at turn at an estimated speed of 40+ miles per hour.
I have nothing to add other than bicycles are generally not built for the load an engine will place on them. They are very dangerous and more so because the rider has no idea how to handle just a device an calamity ensues.
I had to work on a POS Huffy that has a gasoline engine attached in a hodge podge fashion. It is a death trap but I replaced the BMX style BB just to get it out of the shop. I refused to touch anything not directly pedal bike related. I do not want to be responsible...take it to a small engine repair shop.
Good luck