Snowmobile into 3 wheeler
 

So I was following a truck today with 2 snowmobiles (or snow machines if you are in Alaska) and I thought what a great reverse trike they would make. The nose has better aero then some motorcycles, they seem to sit a bit lower, and a full aero body would be easier to build on one then a motorcycle. The skid mounts where the front wheels sit seem far enough forward and outboard to allow for a nice wheel faring. Then I googled it and saw that it's already a thing.
https://youtu.be/KqcL9-6gKDI
http://thekneeslider.com/images/2012...nversion-3.jpg

Those are interesting, but I don't think they could be registered/plated for legal street use. Not In WI anyway, as far as I understand it.

It should be the same as if you started from scratch building a trike. You would have to add turn signals and front brakes and whatever else local saftey laws would require. I wouldn't keep the hot 2 stroke most sleds have, you could even go electric. Snowmobiles with blown motors are cheap, but the basic frame, steering, and front cowl seem to be a great starting point for a homebuilt reverse trike.

I love it! if just for the WOW factor.

Patent US20100044134 - Snowmobile conversion kit - Google Patents

This is how the big company is doing it. I would change a few things, mainly the motor and clutch setup. I also think a simple racing go-cart front spindle and disc brake setup would work fine for about $100. Then the whole body needs a streamlined pod and a reclined seat with handlebar extentions. Maybe put airplane wheel farings on the front tires if room to turn still.

Well I found a $150 1991 snomobile on Craigslist with a blown motor but the wife is not convinced. She says how many toys do I need? I guess I need to sell my CB550F first. I tried to explain, this is different, this is for science.
http://missoula.craigslist.org/snw/5454667590.html

You'd likely be much further ahead buying a running sled in decent condition. The buy-in is cheap on that one, but rebuild prices could easily rocket you past the cost of a running sled.

Pretty sure he is planning to go electric with it.

Because of the size and layout, you should have plenty of room for a motor and batteries.

Based on a conversation I had with a DMV employee that handles a lot of the motorcycle issues, I don't think you would have an easy time getting it registered in WI. Hopefully that's not the case for him.

No way I'd want a 2 stroke with a snomobile clutch. Maybe a motorcycle motor and transmission, maybe electric. I don't think the DMV part would be that difficult, but Montana is pretty hands off. Just like homebuilt motorcycle, maybe just use the registration for the donor motorcycle instead. What part do you register, the drive train or the body? I have thought starting with a 2wd quad might be better just because it could already have liscense plates and registration. Then convert the dual back wheels to a single, that also might have fairly efficient smaller 4 stroke already in place.

Bombardier makes snow machines.

They also make the Can-Am Spyder:
Can-Am Spyder: 3-Wheel Motorcycles for Touring, Sport-Touring, & Sport | Can-Am Spyder US