I tried out my MM esc with a different motor and it works perfectly. So the little bit of sand in the motor is the problem. The Mamba Max controller is amazing.

I got a reply from Castle Creations saying that it would cost about $40 to repair the motor. I like taking things apart I may just go ahead and try myself. MetalMan was it hard to get open? If it's going to get damaged, then I don't know.

The issue of making it so difficult to open the motor to me is kind of a downside. I don't think I have ever had a motor that I haven't had to clean at some point. Even with the best sealing job junk gets in.