Just purchased a new pontoon boat in Nebraska & brought it home to Wyoming. The boat has a 1994 115 hp Johnson on a 24' pontoon. There is a difference of 6300' in elevation from where I picked it up at & where I live. Is there anything special I need to do to the motor to adjust to this new altitude? Is there a "rule of thumb" at a certain elevation change when I need to re-jet the carbs?