2007 VX Deluxe not running at full speed

[rebartolo]

This vehicle is fairly new (only been used since May 2010 - 21 total operating hours). Recently I added some oil as it seemed a bit low. When I drove it again, there was a bit of white smoke. I took it back to the dock, checked the oil level, and decided to syphon a bit of oil out to take the level closer to the mid point between low and high. The seemed to run fine afterward, but lately is running a lot slower (previously topped out between 55 MPH and 65 MPH, now topping around 35 MPH and definitely not revving to top engine speed). I'm wondering whether an electronic rev limiter kicked in for some reason (the "reduce speed" setting is not engaged). I am about to take it to a dealer to trouble-shoot/service, but I thought I would see if anyone has any ideas.