Never had a Fazer but there are many things that can cause this, few of which have anything to do with the steering.
First, check to make sure all four tires have drive. A broken dogbone or stripped wheel hex or something like that will cause all sorts of problems.
I suspect the problem is a lack of traction with a shaft drive. Shaft drive cars suffer from torque steer, especially if the tires break loose under power. I doubt the stock tires have a lot of grip.
Sean. Certified speed crazed mowron.
Team Shepherd USA