bansheEatr
05-18-2005, 01:33 PM
I have a 2000 400ex all tricked out. I have the Keihin 39mm FCR carb with the weisco 440 big bore kit, 12.5:1 compression. With full pipe E series header pipe included, Stage 2 hot cam and brand new high flow aluminum air intak box. Why is my quad back firing sometimes? I thought it was because the motor is very moded? And does neone know how to adjust this type of Carb? Keihin FCR 39mm. I would love some replies. Thanks and keep on ridin.