Originally Posted by Grouik
A 16.000 feet pass with a 1982 R100:
I am on the leave for a week trip between Chile and Argentina.
We are going to ride the Passos Aguas Negra at 4.800 m (16.000 feet).
I guess the carbs needs a special tuning.
Could you please tell me what to do, a small picture would be welcome.
Thanks in advance
The vacuum control of the slide should help, but if it seems to be running rich, take the tops off your carbs, and lower the needles one notch for each 5000 feet, or until you get to the highest notch on each needle. The needles are moved by twisting them carefully, 90 degrees in either direction, then either pulling (to lower) or pushing (to raise).
There are (I'm pretty sure) 5 notches, and most bike have them in the middle notch.
Beyond that, it helps a bit to remove the air filter (or maybe not, if you're going to be on dirt roads!). Just remember to undo everything as you come down in elevation, or you'll be running very lean.