Is there a method to test speed controls. I have a speed control that seems to restrict the motor and battery power out put. When using this control with motors and batteries that have been used with a different control I lose as much as three tenths a lap. How can I check it or compare it to the my other control other than on track? Also can this be fixed?

Use a volt meter, check the volts at the pack, and compare volts at the motor leads at full throttle. There will be a small variance .01V or so not doubt a result of wire/solder etc...

Tom