2 NiMh in series

[BrianG]

Don't know what's causing the "funly chicken dance", but you don't want any kind of lipo setting when running NiMHs. So, when running NiMHs, shut it off. When running lipos, set it to the correct value (can set the voltage you want via the Castle Link). To eliminate ESC setup issues, set ALL the Castle Link settings to default values and start over. Still don't know how you can have such bad runtimes even with improper settings.

Are you shifting into secong gear ever (assuming you are still using the two-speed setup)? What pinion/spur are you using? Are you using a center diff?