Yep, I was writhing this at the same time, lol.
Some people are lazy and just don't care about the bike they are selling. If a bike has no title and it's over 15 years old, it's probably just lost and not stolen. Especially if you can tell it has been sitting around awhile. But, I would always run the VIN # with the above links or, as I've done in the past, just call the local police department and ask them to run it. It worked for me once.
A no title bike should be CHEAP. Because it's just a pile of bolted together parts when being sold. You are going to have to all the work to title it. Also, just because it has a title, doesn't mean it's free and clear either. Just about all the fixer uppers I have bought that did have a title, most were in a different name other than the seller. In this case, I make the seller fill out the bill of sale in that titled name so I won't have any problems at the DMV. That's probably not the right thing to do, but the DMV is so damn picky here in Florida that I'm just trying to avoid any hassles.
For newer bikes, if the seller has a title, it could also have a lien. How could that be? Well, last summer I got screwed buy a guy who lives just down the street from me. I bought an '06 LRT450R Suzuki quad for $3800. He had the title, not in his name of course, so I thought I could do what I had did before when transferring the title. Not the case, as this bike was repossessed and sold at auction. Then sold to my neighbor. The bank, GE Money, didn't file the proper paperwork with the state of Florida so the lien wasn't released. I had notarized documents stating the lien was released but wasn't good enough. I never should have bought this one since it was a high dollar sale. The bike was awesome, but I really felt sour about the whole thing. I sold it a few months later with no title and a $900 loss to a freestyler who didn't care about a title since he rides on private land.
I have bought 4 bikes that had no titles, a CM200T, CB550, VT500C and an ST90. They were all cheap at $100, $100, $300 & $100. I used a title service called International Title Service,
http://www.its-titles.com. I know for a fact that the CB550 was titled in Florida before and was sold to me by Jason Funk, who was working for Brandon Honda and talked an old guy out of fixing it and sold it to him cheap and under the table, he would soon later murder an insurance agent and is now sentenced to life in jail, but that's another story.
http://www.sptimes.com/2005/03/24/Hillsborough/Killer_of_insurance_a.shtmlI had no problems at all using the title service on all four bikes. The older the bike, the easier and cheaper it is to use. Aside from knowing somebody in a state that doesn't require titles for old bikes, this is the only way to go. You sell it to them, they sell it back to you from another state. Take the paperwork to the DMV, done.
I know this is a long post, but those are my experiences.