Anyway pictures speak louder than words:

If this disappears again here's a direct link that should always work:
http://rides.webshots.com/photo/2286111 ... 4206ZlUrJo
Honestly it looks exactly like and reading about options sounds just like the YDS-3:

But I clearly have only ONE cylinder, spark plug and exhaust pipe. I also have no frame in front of the engine so then I really started to lean toward the YG-1:

So were there YDS-3 or other similar bikes that had smaller engine sizes? I think mines clearly from the 60s based on the rubber pads on the tank, did they have a revival model of this in the 70s? Is it possible that my engine has been swapped or autolube added to a YG-1?
Also where is the ignition switch for these bikes? I see a very small key slot in the headlight itself, is this the ignition? How can I remove the headlight cluster to pop out this cylinder (I need to have a key made to it, bike came with no key)?
As for identification help, I haven't written down the VIN yet (number on the triple clamp/steering head) because I have not found any sites that show a VIN range or VIN lookup or list of VINs for certain models like I've found for other bikes, can I use it in some way and is the VIN or just something else? Because I want to know which I'll list when I try to register.
There's also a number on the top of the headlight, YHA-3, but searching it looks like this is just the headlight case/shell's part number?
Thanks a lot, I'm just very curious and want to verify that it most likely never had a title before I try to register it and I want to know what I'm buying parts for, are there any suppliers for bikes this old, things like carb or petcock rebuild kits? My tank and I'm sure everything else in the fuel system is VERY disgusting. Everything looks quite solid on this bike besides some surface corrosion and I can't wait to try to kick it over. 1620 miles on it.[/img]