Washington State has a new law taking effect Jan 1 allowing dirt bikes to be registered for street use after installation of a dual purpose kit and inspection by the State Patrol. Emissions (2 vs 4st) is irrelevant. I do plan to go forward with this (using the ‘86 CR500). This used to be done all the time but a couple of years ago the state started clamping down. But during the last legislative session the new law was passed and the governor signed it so we are back in business.
Federal law says different - going to be interesting to see who wins that one.