try a KB45-10L motor. it is perfect for 5s and has about the same output of a cc/neu. the only downsides are you have to grind the shaft or bore out your pinions for it and you will need a custom mount.
http://www.hobbycity.com/hobbycity/s...hless_Inrunner
They say a good mechanic only needs 2 tools - WD40 & Duct tape. If it moves, and its not supposed to, duct tape. If it doesn't move, and its supposed to, WD40.