Worthless without titles.
I went through the process of getting a title for a bike with no paperwork last summer here in Seattle. It was pretty painless.
What you need to do is well documented on the WA DOT web site. It varies a bit depending on whether your bike's VIN number is still in the system or not. I'm told that it falls out of the system after 7 years of inactivity. A vehicle from out of state will almost certainly not be in the WA system.
I took my VIN number to the local licensing agency and they ran it for me. Nothing.
My particular bike had been abandoned 25 years ago so there was no determining the last owner. (I knew everyone who had possession of the bike in that time but no one knew of the original owner.) If your bike is in the system you have to send a release form via registered mail to the last known address.
The license agency person told me I really needed to have a Bill of Sale. You can do the process without a Bill of Sale but it is more complicated and time-consuming. Everyone understands this is usually a work of fiction but it is the document that gives you the right to "own" the bike and pursue the paperwork. I wrote a Bill of Sale from my wife to me. In WA there is no sales tax for family transactions. We had it notarized at our local credit union for free.
I then made an appointment at the WA State Patrol inspection station. It took about 3 weeks to get a spot in line. The inspection is partly a stupid test. Is the VIN on the Bill of Sale the same as the one on the bike? Doh! He then looked up the VIN to determine that the vehicle was what I said it was on the Bill of Sale. 1978 Yamaha XS650 - check. Paid the inspection fee and left with stamped paperwork. In WA you have to have a complete vehicle to get an inspection. I have no idea what 'complete' means. Probably road legal.
Back to the license office, paid the fees (minus the sales tax) and got a registration / title application. Since my bike was over 30 years old I paid $50 and got permanent Collector Vehicle plates. No more annual tab fees - ever.
Here in WA you get an actual title in 2 years. This is the state covering its behind in case someone pops out of the woodwork claiming the bike. I've never heard of that happening. The bike is completely legal and can even be sold. In WA selling it requires a notarized Bill of Sale for both seller and buyer. The two-year waiting period is not reset.
So yes, it is a bit of a nuisance but for a nice bike it might be worth it. Apart from the inspection it really isn't any different than a normal transaction.