You know I'm not sure. I've tried to call them and I'm waiting for a call back to give me more information. I think it might be 5mm, and although I can find the replacement part, no specs on it are listed.

http://www.horizonhobby.com/Products...ProdID=PRB3102

http://www.proboatmodels.com/ProdInf...nual_LoRes.pdf

Thanks for the info on the motor, I'll order that asap, now just need the prop and I'll be doing great. Do you know if the esc will handle a 3s lipo or would I need to get the esc reprogramed or something before hooking one up?