What cam are you using? The carb may not be jetted correctly for idle, slow speed jetting, high speed jetting, and/or the VOES needs adjustment. The HI-4 should not be used in RACE ONLY for stock bikes and it should not be grounded.
Remember reformulated gasolines need richer jetting.
Try this for the VOES:
VOES CALIBRATION (specific to Evo engine models only)
The VOES has a vacuum line that connects it to the carburetor. Remove the switch from the bracket and the vacuum line from the carb. Connect a vacuum pump to the fitting on the switch. Hold the switch close to your ear and squeeze the vacuum pump slowly. When you hear the switch “click”, stop squeezing and look at the gauge to see how many inches of vacuum it took to open the switch. It should be between 3.5 and 4.5 inches of vacuum.
On the back of the switch you will see a rubberized coating over the calibration screw. You need to remove all of the coating to access the calibration screw. Use a toothpick, small blunt punch, or a jeweler's screwdriver to remove the coating. Be careful not to gouge the threads of the switch as it is made of plastic and can be damaged easily. Calibration is a means of turning the screw until the desired reading is accomplished.
We want the switch to open at 6 to 8 inches of vacuum (for high compression pistons (10:1 or more)). If for some reason you cannot hear the switch click, connect a DVOM to the leads of the switch specified in the owner's manual and follow the instructions. During calibration, it is imperative that you hold your thumb over the portion of the switch that houses the screw. After calibration is complete, fill the cavity with 3M-weatherstripping or RTV silicone. Let the switch cure then reinstall.
(from HemiDesign Heads)
Do not use Race Only.