Let say you bought motorcycle with bill of sale only.
Make an appointment with the local CHP for VIN verification.
On the appointment day, bring you motorcycle, bill of sale (reg 135 form), all paperwork (old registration) and reg 227 form(or the CHP will provide you one). The engine has to be attached to the frame. They will not do VIN verification for the frame only.
CHP officer will check the frame number, vin number, and engine number, they will check the national database (takes about 15 to 30 min). Then the officer will fill out the second page of reg 227 form.
Fill out the first page of the reg 227form also
Fill out reg256 form item C,G,H
On item G fill out with these information
---How, when, and from whom the vehicle was acquired.
write "i saw the add on craiglist and bought it from mr.x on so date"
---What efforts were made to obtain evidence of ownership and why it was unobtainable.
write "mr.x tried to find the title/registration of the vehicle but he could not find the paperwork since the motorcycle had not been use for more than a decade and been abandoned in his garage/property"
---The current value of the vehicle.
write "I (your name) bought the vehicle for $ -- per current value for the condition of the vehicle when it was acquired."
Bring all the paperwork to dmv office... you don't need to bring your bike. Pay the fee for retitled (cost about $150 ish)
They will give you registration And plate (if you decide to do non-op, they will not issue plate)... They will send the title by mail.
And you need to buy insurance...or dmv will send you a letter to cancel your registration.
hope this help