Make sure the exhaust flap isn't stuck open. If its stuck its £1200 for new headers to fix. If its stuck it will throw a code that is visible if the bike is plugged into the mothership computer. When you switch on the ignition you should hear it close and then open again.
Also have a good look at the engine and swing arm to make sure there is no corrosion under the paint.
If its a dealer bike they should sort.