What's the story on old bikes w/o title
 

I periodically cruise CL and ebay looking at small CC bikes from the '60's and '70's and often there is no title. How big a deal is this? Enduro bikes really have my interest (4str, 125cc, knobby tires-like a slightly bigger, funner version of my cub) so maybe title isn't such a big deal but i worry about stolen bikes as well.

That is somewhat of the same type of problem that I have when I buy another one of the 1948-1953 Dodge trucks that I restore. A lot of states did not even issue titles until the mid 60's. I have had to go through the process of obtaining a "Bonded Title" as the name implies, you have to purchase a title bond from your ins. agent, then do the paperwork at the courthouse.
If they are going to be used as a street bike, I would think that they would be regulated as any other motor vehicle. If you are getting one for TT, or track work, and it was not going to be used on the streets, you can still verify the VIN or Serial number with the state to see if it was ever titled and who the last registered owner was. If it is the person that you are buying it from, they could get a replacement title. If no records are found, about the only thing you can do, it get a bill of sale, and do what ever paperwork you need to, to register it with a "bonded title" or go through a title service agency. Good luck!! Tony.

If you can prove it's not stolen and dont plan to get tags, it's not an issue.

I do it a lot with bikes as I used to have 22 and am now down to 14. It really varies from state to state. In my state (WA), DMV will take the VIN and do a check for the previous owner. If they come up with something, it's up to me to track the person down and get a notorized release.

If a certified letter returns, DMV will register the bike to me, but no title until 5 years have passed and no one claims it.....Check you local DMW...