Ok I just got a Murray wide-body that the motor has been changed out to a opposed Briggs. And at first It would just over rev the motor. I adjusted the throttle cable and now it idles fine. But now it will not idle up. It will move the butterfly fine with the motor turned off. Just not while it is running. The cable is adjusted right. Just its like the governor is not opening up while the motor is running. No clue on how to fix it. And if I throttle it up by hand on the linkage it revs just fine.