Unfortunately, producing an entirely new product from scratch is never without initial problems, and the Vision suffered from a few. An off-idle carburetion quirk, known as the
"Vision stumble", meant the first year machines were prone to initial stuttering on part and full-throttle takeoff. The "Vision stumble" problem, after months of research, was finally solved by racer Marc Salvisberg, who later started Factory Pro Tuning. The problem, it seemed, wasn't a Yamaha development problem at all, but was actually a lean spot, just off idle, caused by what appeared to be residual casting sand that filled the off-idle bleed holes at the throttle butterfly plate in the Weber-style Mikuni carb. That information was immediately relayed to Yamaha U.S., where it was relayed to Japan and verified.
The 1983 models carbureted essentially flawlessly.
Still couldn't go wrong at that price could you?
Here are some reviews. It seems the stators are a problem.
http://www.motorcyclesurvey.com/reviews/yamaha/xz550_vision/http://www.xz550.com/