Re: Dohc carbs at higher altitude

Posted by LukeM on Aug 15, 2012; 12:39pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Dohc-carbs-at-higher-altitude-tp4027138p4027148.html

There's less oxygen at altitude, so leaning out the carburetors is what's needed.  I'd start by turning the mixture screws about 1/2 turn at a time, and then doing a plug reading after a tank of gas.  My guess is they'll be a bit black and sooty now due to the richness.  You're aiming for a light brown color on the insulator.

If memory serves, turning the screws IN on those carbs will introduce a leaner condition.

If you run out of adjustment, you may have to go one jet smaller across the board.  The FSM (on the front page of our happy little forum) should have the factory jet sizes.  Check yours when you get them off the bike, then go shopping.

Luke M