carb tuning at sea level but usage above 7200' 1966 9.5

after rebuilding my 1966 9.5 hp johnson carb i set the low speed needle valve in all the way and backed it out 1.5 turns, tested and ran great at 1100' above sea level....Question

I use this engine at 6500 to 7500' above sea level...the low speed adjustment knob moves 180° from stop to stop without having to remove the front plate and c clip to get more or less turn...is there a rule of thumb to set this up for the higher elevation usage, set it richer at the lower elevation so it does not run too lean at the higher elevation? or is it just a SWAG calculation? thanks for any and all help....jzona

Re: carb tuning at sea level but usage above 7200'

I think you have that backwards.

At sea level the air is denser than at elevation.

At 7000 feet the motor will be "air starved" not fuel starved. So if you fiddling with a needle valve that controls "fuel flow" you would want to set it lean at low elevation to prevent an over rich mix when it has less air at elevation.

If it was even a little rich at sea level, it would be almost "flooding" when it loses it's air supply...