Will a 1/3 horse power sump pump motor burn up at half power?

[hipsterjr]

Please do not take this the wrong way, but coming from someone who has built homemade/ non-first robots, I can see that you may want to do a lot more studying on basic AC and DC electrical circuits and the wide variety of electrical motors before you get too deep into this project. At your level of experience, I would stay away from AC motors all together and stick with dc. AC is possible, but take a lot of know how to work on a battery powered robot. I took a digital circuits and industrial controls class that really helped me understand some of the questions mentioned here. I don't want to discourage you at all, just know what you are getting into before you spend too much time or money on something that won't work.
My $0.02