The motors you installed are not correct. They are really fast because they're running twice the speed they would at 12V since the wheel runs the motors at 24V. That means they are also trying to draw twice the current they would at 12V. Excess current draw pulls the voltage down and shuts the wheel off because the power supply can't keep up. (Your link says your motor stall current= 11.8 amps @ 12VDC. At 24VDC, the stall current for both of those motors would be an astronomical 47.2 amps! Stock power supply is good for about 5 amps @24VDC. You need a motor that stalls at 3 amps or less at 24VDC if you want to use the stock power supply).
Wow thanks guys @eKretz @Phlano099 for the detailed concise replies its a lot clearer now what motors I need, I think I spent so long looking and got a bit confused as to what I required, but it seems the original motors are pretty much unavailable now, but as luck would have it there was 2 Used QK1-1500's on eBay which I've snapped up, hoping to get the wheel back up and running thank you again