Pulled the plug on the 2003 400i auto and noticed its running too rich...very black. I normally run about 4500-6500ft range. Went to some taller hills and run around some trees (90 miles one way trip just to be close to trees) I was close to 8K ft a few times and mostly ran about 7500ft for about 18 miles.
Do I need to change my jet and needle for running at higher elevation? If so, how hard is it to do. Some time later this year I was going to grand mesa, colorado and run at about 10,200 ft ele.
Is there a kit that can can jet sizes in the field?
Thanks
Roger

 

I hope this helps..

 

On my 03 400i, the main jet was changed to a 145 and the fuel screw to 1.5 turns out (was 2.5 turns out from the factory). This cured the lack of power and surging at higher elevations.

 

RogerL,
Put the same setup that DaveB is running in his machine, and you will be fine for 4-8000" feet. Also go talk to your dealer about the hi-alt. clutch mod.