well... the thing is, this is also for california registrations. each state has its own set of laws and regulations when it comes to these matters. so, beyond it not being a moped, the laws are also different due to the state you or the bike resides.
if it is in california, however, this is how i would take care of it. the landlord, you said also wants to get rid or it, correct? get him to fill out a bill of sale that states he currently owns the bike and has sold it to you. take the bill of sale to your local dmv office .
at the dmv they will read over the bill of sale and have you sign an affidavit that states you know personally know the seller (in this case the landlord would be filling in for this part) and that the seller sold you this bike lawfully and knowingly (even though he kind of didnt). after signing this, you would then pay the needed fees and the bike would be on your way.
now, if the original owner is long gone and you could never find him, this would be the way to go. if you CAN in fact find this original owner, i would do it the completely legal route and have him sell it to you and get him to fill out the bill of sale. the key thing to remember is, the registered owner DOES NOT have to be the one to sell you a vehicle. the vehicle in question should just have been bought or sold by a new owner who didnt steal it and it should be fine. i do not in anyway condone stealing but sometime, mopeds included, youll find bikes that people have completely abandoned. these bikes shouldnt just waste away, so do we do what we can! in this case, i kind of see the original registered owner as the landlord, since the original owner seems to have abandoned this bike... seems ok to me?
KEY THINGS TO REMEMBER HERE
-THIS IS NOT A MOTORCYCLE FORUM (but i answered the question anyway)
i have answers this question but if you are here for moped reg questions, read above information NOT THIS. you dont need a bill of sale or anything of this nature for your moped. ive made that pretty clear in other posts.
-THIS THREAD IF FOR CALIFORNIA ONLY
each state has its own set of regulations and rules when it comes to their dmv registrations as well as their drivers license requirements and so forth. so if you are not in california and have a moped, there is only so much we can do here to help BUT i am always willing to try. email me if you are in another state or have something else you want to register! i can try to help. hahahaha
-I DONT CONDONE STEALING OF ANY KIND
this is the conclusion i have come to due to the fact that the original owner has completely abandoned this bike and has basically left it for rust. otherwise, this wouldnt be a great option. ALWAYS try and go the correct and legitimate route first! if you get caught into a situation like this, however do what you gotta do, i say! but do make sure the original owner is long and gone or doesnt care anymore. you dont want them coming back and finding out you own their bike now and report your ass to the dmv. also, im not hear to help you register your stolen ped or bike, so dont even think about it here!
GOOD LUCK WITH THE REG*