Cold weather carb adjustment advice needed quickly

I am racing a STC series MX race this weekend near Houston on my 00' 426 and the high temperature is supposed to be 39 degrees. (We have been lucky during the first 6 races of the series and the average temp has been in the mid 60's). My carb settings are 100% stock and the bike runs great (but I haven't ridden it much below 50 degrees). Will the stock carb settings be too lean in the cold temperature? Can I make any minor adjustments (i.e., no jetting changes) that will get me through the weekend? Thanks in advance.

For winter riding here, I usually just mess with the fuel screw. You'll only have to do this if the bike pops when decelerating, otherwise just ride it, and good luck...


Under 50F cover half of one radiator.

Under 32F cover one radiator.

Adjust the fuel screw OUT to richen as necessary to keep the decel popping at a minimum. Worse is if your idle is "hanging" a little high - fuel screw adjustment will help this too.

You may want to change the clip position on the needle as well.

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