over voltage power supply with low voltage servo motors ?

Hi all,

I have two problems.

#1 is that I need 9 volts to power a small motor on an e-bay special.
9 volts and 10 amps max.

I was thinking one of those hobby motor speed controls.

Second, how silly is it to run a 24 volt servo on a 35 volts power
supply ?

can I just limit the top speed to, say, 65% so the voltage is limited ?

Dave