Hi i hope i am not repeating myself I am new at this just a couple of days into this help forum. I sent one out last night but do not see it posted might have made a mistake so i will try again. thanks for your patients<br />We have a 1989 johnson vro 120 hp on a 1989 wahoo 18.5ft. When the throttle is all the way down the boat won't plane out. Could it be the trottle cable or the spark plugs we put in the correct ones last week checked them the other day and they are all dirty we have only run the boat a short distance twice because we can not go fast. any help would be great thanks