Found out that they make an alternate larger rear pillion. As for them switching motors, I donĀ“t think they will do it for 2006 but probably for 2007. The reason is because there are stricter emissions for 2007. They will increase the displacment to keep the power up in order to cope with this. The net result probably will not be a gain due to the effect of compliane with emissions. This is just a guess on what they might do.