If using a 3-line setup with two clunks, you may encounter issues. I did when I tried it with an ST S90. When coming off the throttle from WOT the pressure line would fill with fuel and the engine would go rich and quit. I didn't have much success in using a 3-line setup where others had success with it. I went back to using a standard pressure line inside the tank (pressure line came in above the fuel level) and my problem went away. Some exhaust systems don't bleed the pressure off quick enough when coming off the throttle in my experience.