Its actually rumored in NZ (and hence AU) as well. A guy on the CBR250.net form says his dealer swears the bike for NZ is 54HP. I'll beleive the rumour mill once they release them here and Australian Cycle News tests them as promised in the April edition.
i doubt they made changes to the engine/exhuast/intake, i reckon the ecu would be slighty de-tuned to meet legal power to wieght requirements in countries with the restrictions. i reckon a simple ecu edit will be all it takes to go from 47 to 54hp
I think there is a cheap mod that we can do to increase flow to the intake for a slight increase of horsepower. For the cbr600rr there was a mod to remove plastic baffles that reduces flow to the filter. I think when we all get the CBR500R we can take a look if this is the case for us too. I'll be putting in either a bmc race filter or a K&N filter.
I have heard of this mod to where people would gut the airbox to increase flow and it does get louder too from what I've heard. Those baffles are in place to keep the volume of air to stay at a certain consistency and also to control the volume of sound. Its a little too soon, but I guess we can look at it once the bikes are out.
Four wheels move the body. Two wheels move the soul.