A brushless DC motor is recommended for a 3-wheel bike to ensure optimal performance and efficiency.
Could be a bad solenoid - jump across wires to test Jump smaller - (trigger wire) to cable that runs to starter
An electric scooter of all types use an electric motor powered by a battery(s) I have a 3wheel scooter and a 4 wheel power chair, both for medical use and use 2 - 12v Lead acid batteries in series to produce 24v DC which runs the 24v motor.