The engine is a 1984 Mariner 200hp. The engine idles perfect but when you go to get out of the hole it takes approximately 70 yards for the boat to get on plane. The engine appears to be stuck at 3000 rpms then finally decides to plane out. The engine used to scream and have no problems getting to 5800rpms with the current prop at high altitude. The stator, spark plugs, fuel pump, fuel bulb, fuel hose, fuel filter, and new fuel have been replaced. The carbs have been rebuilt. The engine has 200hours but set for 8 years. The red wire coming from the idle and timing module were heavily corroded on both ends. When I attempted to find a replacement I found the module is no longer manufactured and it was advised to do away with the module since they are not needed anyway. I am in the process of setting the timing both idle and WOT. The boat lives at 6000ft. above sea level. Do I make any adjustments for altitude when setting the timing? I realize there may be other issues present, but I am attempting to eliminate one problem at a time for an older gentlemen as inexpensively as possible. Thanks for your assistance.