Posted by KauffmanM on 07/14/11 - 5:23 AM
#1
Has anyone ever had issues with the jets in there outboards going from sea level to 4000 ft. it has something to do with leaning out the gas. My outboard has .061 sea level jets in right now & I jus got new jets to install, they are .063. I planned ahead in case there is an issue. The boat is still at sea level so I dont know what will happen when I get it up here to Idaho. Its a 1974 Mercury Thunderbolt 500 50hp. Runs awesome right now. Thanks for any input or advice given.
Edited by Joe Kriz on 07/14/11 - 3:36 PM
Posted by summitwhaler on 07/14/11 - 7:16 AM
#2
I believe you want to get slightly smaller jets to make up for less oxygen at altitude. It just takes a bit of trial an error. You can also try a reduced pitch prop. your max rpm at full throttle might be lower at altitude. 4000' isn't too drastic. My local marina is 9000' it took some tinkering to get my motor running good.
Posted by CES on 07/14/11 - 7:34 AM
#3
Summit is correct. You'll need less fuel as you gain altitude to keep from running too rich due to the lack of oxygen. Smaller jets would be beneficial at altitude.
Posted by KauffmanM on 07/14/11 - 2:26 PM
#4
I think I will just install the new jets for my altitude change. Thanks, just wasnt sure that 4000 ft was going to make much difference.