Should the vacuum tube be hooked to both intake boots or is one enough. I currently have mine hooked up to one and a cap on the second. Bike runs fine at idle, runs fine a highway speeds but after running a high RPMs for a while, when slowing down at a stop (without gearing down, just pull in the clutch a brake to stop) the idle drops way down and it stalls. If I give it a little throtle just before stopping it comes back and no problem.