It will depend on a few things. What capacity battery are you using? is it a 540 or 550 motor and what type/size of nitro motor are you trying to kick over.
Usually starter boxes are run on 12v dc if using a gel cell or 14.4v if using two stick packs and either have 1x550 or 2x550 motors or some even have just one big ass motor in it, these would be more for your big block motors.
The starter box i use for my 1/10th scale tourers has just one 550 motor in it hooked up to two stick packs = 14.4v