The BW 80 was two stroke.
RVs are like Rokons as in they are utility/ag bikes. The BWs and FatCats are play bikes.
The tire pump on the RVs was a neat idea. The RVs were also street legal and had a H/L sub trans.
A friend has a BW200 that needs some major attention, it hasn't run in years. Last time it was running he had just put a new CDI on it. From the exhaust smoke it looked like a two stroke running 1:1 mix. I would do anything to stay in front or I couldn't breath. I think his clothes were combustible at the end of a ride.
I staired a whole thru the breaks until I remembered the carb prolly has a problem to and I'm gonna hafta work on em.