My son's Viper with Bender/Opticool/RHE has been running 167/55 for 3 years with no problem. We did have the pipes ceramic coated. Make sure you check your exhaust valves/cables. He had one burn-through on #3 (mag) and a rub-through on the center. I'd have to check the recs, but at 1200 ft/20 degrees with 167/55, I'd be inclined to think it's a mid-range burn down related to the needle clip position. IIRC though, he runs at 2 1/2 here and 3 in Montana (6000-8000 feet). We did not mod the airbox.extreman1 said:needles are stock setting and fuel screws are at 17/8 turn, elevation is 0-1200ft when in burned it was +20 degrees.