You sure it's the motor? Have you tried them in a different setup (esc)? Is it the stock esc?

* It maybe esc issues and the esc is either bad and just not working or bad and destroying motors.

If you look at the specs it's only rated at 15t motor& 40amps http://www.horizonhobby.com/Products...314#quickSpecswith that being said the titan 12t probably damaged the esc and now the esc is just taking motors out. Just a thought and I maybe WAYoff.... Lower the turn normally more amps it can pull. its higher topend less torque so the motor could have pulled to many amps. Like Isaid just a thought I could be way off.