Need help with gear motor please

I have a Bodine gear motor that seems to be not working properly and I need to get it working if possible.
The motor is a 115v ac motor with a 90:1 gear reduction that should spin at 19 rpm (see link to motor below). When I got the motor (used) it was wired up to a toggle switch and a standard 3 prong electrical plug. However when plugged in and turned on it seems to only spin at about 4 1/4 rpm not the 19 rpm its rate for. Bodines website states that it should have a 4 MFD capacitor for it to run properly and this motor does not have the capacitor installed, could that be the problem? Or perhaps its wired incorrectly, there seems to be two sets of wires that go into the motor. Can someone possibly suggest something to look into, I have emailed Bodine, but got no response.

Here is the link to the motor:

http://www.bodine-electric.com/Asp/P...tor&Model=5461