Does anybody know what is a good way to test a motor (in this case a treadmill motor rated at 130V, 2.5HP, 18A.

 

??? You want to use a motor to generate Wisconsin Democrats? ???

 

It will have to be a DC motor. If it's permanent magnet (not likely), then arranging to spin it from another motor and putting a load on it won't be too difficult.

Fro one that size, you would need to feed a current to the armature to create a field and then measure the output under load.