Uh oh... here in FL, you'd be screwed.
If the bike was titled to 'A', and 'A' sold it to 'B', and 'B' filled out his name as buyer, but never transferred the title to his own name, then sold it to YOU, the state of FL would say - "bring 'B' in here, have him transfer it properly and PAY ALL THE RELEVANT FEES, then we can transfer it to you and you can pay those same fees all over again". And if 'B' wasn't available for whatever reason, too bad for you - NEXT!
Good luck with it.
Kirk
*edit* on the other hand, if 'B' never put his name anywhere on the title, then you CAN just put your name in as buyer and "pretend" to the DVM that you bought it directly from 'A'.
Y'see, as far as the DMV is concerned, you DID NOT buy it from the previous owner. Legally, 'A' is the official previous owner and you bought it from 'B', who legally had no right to sell it to you. Anything you do at this point is an attempt to wiggle around that fact.
K.