ok here goes I have a merc control with new cables,I have the shifting part work fine but the throttle side is driving me nuts. heres whats happening when I put in in forward no problem but when I put it in reverse motor revs up full throttle...what am I doing wrong. I can not find anything in manual that helps me make sense of it...this is a 50hp mercury with mercury controls on a pontoon boat figured I mention it not sure if it matters...thanks in advance Phil