Altitude/jetting/octane

[trout]

I have only had a cannondale, and it had EFI so I have never dealt with a carb. I have a question on altitude.

I live at 7000 ft. and often used to ride up to 10-11000ft. Up mountains here in colorado.

Properly jetted, will the 450R(or any carbed quad for that matter) get the same performance as it would at sea level?

I would think not, but I dont know if jetting properly will allievate the problem. Anyone ride up as high as I am going to??

Furthermore, since there is less oxygen in the air up here, the highest octane you can buy from the pump is 91. Something to do with the amount of oxygen in the air that will mix with the octane, apparently you need less up here, do you also need less octane in your quad at altitude??

Thanks for you time,

Trout

[trout]

any thoughts??

[trout]

anyone? anyone? Bueler? Bueler?

[snow4fun]

Trout,

I live in Utah and ride between 4,000 & 5,000 feet. I have always heard that for every 1,000 feet in elevation you will lose a certain amount of power that you can't get back. About the only thing you can do is bump compression to help make up for it. Also my local dealer says they normally take whatever main jet is recommended for sea level and multiply by .95 to come up with the right main for our elelvation. So a stock TRX450R has a 118 main and when I checked mine after dealer setup it had a 112 (or 118 x .95 = 112). So there are some things they try to do to compensate for elevation but any bike should not run as strong at a higher elevation as it will at sea level unless modifications are made. I am not sure why the Octane at our elevation is only 91 at the pump and sea level guys can get 93. It must have something to do with elevation. Take Care Scott in Utah.