I was told, but have not personally verified, that the ignitions/flywheels on all of the 2011 models is the same, with the exception of the ring gear that is added to the flywheel on the e starts. This is not to say that the flywheel on the 125s is the same as the flywheel on the 300s. What I mean is that all of the 300s have the same flywheel, all of the 250s have the same flywheel, etc. The ring gear has to add some weight but I don't think it is significant.