The 5043 needs a 4mm to 1.5mm adapter. There are a number of types and sources. See my blog thread on the topic for info & links: http://www.rcgroups.com/forums/showp...73&postcount=1
Also - good modeling practice dictates that adding dead-weight to a powered model should be a last resort. Especially when the model has a marginal power-to-weight ratio in the first place. For those who would rather not reduce the performance of their F4U by adding dead-weight, but don't want to have a battery hanging below the plane, see the pics below. See the video for an example of the performance you'll get, and to see that the battery isn't visible in flight.