With the 14.76 gears and 22.5 diameter tires your turning 5515 RPM at 25 MPH. Thats the top of the mark for a stock 7hp motor.
At 30 mph you would be turning 6618 RPM A Ride For Fun Motor will live at this level.
Stock motors are happy at 5000 RPM and maybe stretch to 5500 with out grenading.
Performance Motors are good at 6000 but can do up to 7000 for short periods.
These numbers have been exceeded by myself and others BUT the last motor I blew also TOOK OUT the controller. EXPENSIVE!!!
I have an interactive Tire size vs Gearbox ratios program in Lotus that gives you motor RPM’s with any combination. rodneyadiehl@aol.com
Rodney