Effects of Altitude

[fortyplus]

Hi, I thought this would be an interesting one to get minds working. I'm running my Forty Plus longshaft at 5000 feet above sea level, obviously on a lake my transom isn't that tall. You lose power at altitude due to the thinner air. You normally have to rejet to allow for this. My motor runs well but I feel its holding rpm and power back, what do you suggest? Would removing the air compensator for example improve air flow? All thoughts aprreciated. I've yet to even see another Seagull motor here in the Rockies, so not able to get any local feedback.