How do you adjust speed of your John deere F525 mower very slow?

check the plate attached to the engine which has the speed control cable running to it from the front pedal. My mower had a missing bolt which connected the plate to the side of the engine. The cable running to it would move the whole plate. This did not allow the cable to change the speed control arm inside hydrostatic assembly. I have to be careful now with the increased speed and sharp turns. Good Luck