All of those snowmobiles sitting around in the summer can make a guy think, what could I do with this when there's no snow on the ground? Some race them on water, amazingly enough and others drag race on the grass, but if you really want to get some use out of it in the warm weather, put wheels on it.
This 2005 Yamaha RX1 snowmobile has been converted for road use and what you have is something that may remind you of a Can-Am Spyder, but this model uses a high performance 4 stroke engine derived from the crazy fast Yamaha R1 motorcycle. Got your attention yet?
The engine in this sled came from the factory rated at something over 145 horsepower, so in a three wheeled sled? Hold on tight. It's easy to see why someone would convert one of these when he starts thinking about all of that power sitting there doing nothing a large part of the year.
The seller doesn't say whether this conversion is permanent or something you can remove in the winter, but he says it is now titled as a motorcycle, so I'm guessing this was a one way trip.
If you're used to the performance of a snowmobile, a Can-Am Spyder might not deliver the thrills you expect. On the other hand, a converted sled with an inline 4 from the Yamaha R1, now that's a whole 'nother story. It's for sale on eBay.