New to the tuning on atv's but it Looks like I am running Real rich. Plug is black and wet after a Wide open run and it bogs on take off. My Question is where is the Adjustment screw and how muck should I adjust it in?

Oh yeh it is a 03 400i auto with about 275 miles on it. 26 outlaw Radials and no other mods except a winch.

Any Help would be nice

 

the only mixture screw is for idle. have you cleaned your air filter lately? if you have done no mods, you shouldn't suddenly be running rich but you describe the classic symptoms. there is probly an obstrution on the air side of the equation: dirty filter, airbox caked with mud or something like that. sometimes manufacturers will ship them a little rich and the slightest air problem will push it over the top. good luck.

 

Take it back to the dealer, why screw with a new bike if it's not runnin right?

 

You need to drop your main jet to a 145 and set your fuel screw at between 1 and 1 3/4 turns out from fully seated. Try that.