Just saw it on craigslist - http://boston.craigslist.org/sob/mcy/486052877.html
Racerat? Part out?

Sounds like it stolen

Ask the guy for the VIN and ask him whats the deal?

It looks clean for only $750.00 and that would make me believe its stolen but if he gives you the VIN have your local PD check it out. If the guy refuses to disclose it then yeah its most likely smokin!  Ask him where it was last registered and to whom . There could be enough of legit reasons as to why he doesnt have it.Main issue is to make sure the VIN is clear so you dont wind up with an arrest record. I have bought a couple bikes with no titles and first thing i did before i even touched it or shelled out the cash was check with my local PD and did a VIN check. Some Pd's wont be as accomodating but it resulted to me buying three clean VIN motorcyles for about $150.00 a piece running.( I say clean meaning not stolen, two of them were salvaged status and only good for parts or track).

Depends on what you want to do, if you plan registering and riding them on the streets i would keep looking for one that has title in hand. Its a big headache half of the time to track a title down. If its a clean VIN and you choose to purchase it insist ahead of time that you recieve a bill of sale at minimum as well as take his personal info down from his drivers license. If you let him know all of this ahead of time and he's still cool with it then you may have a great deal, if he refuses then walk away from it.

Get more info first from the seller and if it dont sound right then dont bother....

I agree, though I'd ask to see the bike in person, write down the vin myself, and run a check on it. if its stolen, call cops then and there on him.