I've gotta differ with Marc on the 406 engine. While it was indeed down a bit on horsepower and technology compared to the Nipponese product of the era, with a bit of fiddling with the ports and an ultra lite aircraft spec rotary valve the bike turned into a formidable weapon. A mate of mine in the USA raced desert on one and won a lot of races on it. He sometimes did a wheel change and rode flat track with it too. I actually bought the bike (an '89 model) but sold it before I had a chance to ship it home (for a sweet little 100% profit to a Swedish guy). I rode the bike and compared to the CR500 that my mate had replaced it with it wasn't near as fast but it handled far better and turned like a Maico. In a 2 hour GP race (a 10k lap motocross/desert race sorta thing) the race times were within a minute of each other.
I later bought a 605 enduro model but once again, sold it before it was shipped home. I'm now thinking of a 250 electric start model from around 00-02. They're as cheap as shite and fast enough for this arthritc old pensioner.