Anyone have any issues synchronizing their stock carbs? I've been trying to synch them and found that the horizontal cylinder doesn't produce the vacuum that the vertical one does (or vice-versa). So I took the air box off and looked at the sliders while revving the engine. I found that the slider for the horizontal cylinder opens up significantly faster & easier than the vertical one. I cleaned the carbs, rebuilt them, changed the seals and still found the same problem. Should I replace the spring on the slider on either one of the carbs?