rejetting carbs after stock exhaust has been removed

[Mikeanthony]

I have stripped down an old Gl 1200 including removing the stock exhaust system. I would like to know what jet size I should go to because of the decreased back pressure. It doesnt run too bad but it stumbles a little at low speeds. Rather than guess about the correct jet to use in this configuration, I thought I would ask the experts here. [attachment=0]0717171441.jpg