First time boat owner...just bought a boat seems like it is very rough when shifting from forward to reverse and it missing the neutral switch on the control box as well ..personally the whole think just look and feel like she has some miles on her my question is how much of a pain is this to replace with a new single throttle control box? How do I know which ones will fit? these are all thing I have not clue about lol..if anyone can give me a school lesson on this I would much appreciate it ...motor is I believe a 1981 mercury model 500 outboard ..unsure of the control model I assume its stock as it says mercury in blue on it as well..Thanks