Unfortunately the stand return spring is weak, allowing the stand to “bounce down” while running, cutting out the engine. There are two fixes; replacing the spring, or bending the factory spring. A good replacement spring is from Moose Racing. Their exhaust spring M7712 at 3.3 in (83mm) is usually used. (see Guzziology) Alternatively, one can take the factory spring and bend a new hook in the end. This shortens it and adds tension. Do this by taking it off, heating the end with a torch, and bending. Don’t let the coils heat up, as this removes their temper.
Joe