Hi all. Recently acquired my first boat, 14ft jon boat with 91 gamefisher 15 hp outboard. I was able to get it running and just replaced a badly damaged water pump impeller. After putting the lower back on, i noticed a black plastic block on the shift linkage that prevents the throttle from advancing past “start” when neutral or reverse is engaged. I can only twist the theottle all the way when in fwd gear. Is this normal or did i throw something out of whack when removing/reinstalling the lower end?