Hey all, so the motor in my GT80 has been replaced at some point by one a couple years newer, with a different vin.

Do I need to register both of these vins? currently I only have the frame vin. Thanks in advance for helping clear things up!

Depends on your state. For example, California have a place for and lists both the frame and engine numbers on a motorcycle title/registration.

Nevada, and most other states I know of, only list the frame number.

If your paperwork has two separate numbers, then you might need a new title after the engine swap. If they only list the frame number, you're fine.

What state are you in?

Just in case any fellow Brits need to know, you will need to tell DVLA of the change in engine number. They will amend their records and issue a new V5. No change to the registration number though.

I'm in NM trying to register my bike, dmv called me saying there is a duplicate Vin in TX registered to a truck. It has been three weeks, and still no answer. Pretty frustrating!

In Calif, with bill of sale bike, non titled bike.

1- go to DMV to start paperwork
2- make appt with the CHP, takes 1-3 months to get appt. maybe longer now with the Covid thing.
3- go to CHP, for V.I.N. and engine number check, to verify year, model, make and if it was originally a dirt only bike. Check for stolen.
4- cross fingers, toes too.
5- back to DMV, cross fingers again.
6- best case scenario, install licence plate and go ride.

*note*, for bill of sale only........if it all possible DO NOT tell DMV its from out of state. They will make you contact the state its from to get DMV record. I found out the hard way, luckily for my bike Arizona records can be acquired online.

This is all by experience.

I'm located in Canada

Your original question almost sounded like you were wondering if you needed two registrations? It's only one vehicle so I seriously doubt that. The question is probably if the current registration needs to be updated if the engine number is different now.

Hopefully a Canadian member can help... or if you have a motorcycle title/registration now you could look and see if they list frame and engine number separately... if only one number, then very likely they only care about the frame number.