Alright guys, need some help we are at a loss on this ski. We pulled the flywheel and the key was fine. Put it back on and set the timing. Still backfiring through the carb at high RPM's. It has also developed a new problem where if we set the idle so it will run on it's own it will ramp up to WOT, giving it gas kills it. Thinking the revving to the moon is an air leak on the intake side somewhere, but we put new gaskets from where the intake mounts to the engine all the way to the carb so it is all fresh gaskets on the intake side and still doing it. Can it be any other gaskets causing the reving like maybe a headgasket or something? Also can anyone explain to me how it is backfiring through the carb with correct timing, because that blows my mind?