jetting 2005 400ex

[05exrder]

i have a 2005 400ex with a moose racing air filter and i sometimes have trouble with throttle response in weather at 80 degrees yet in 60 degree it has all the power in the world should i maybe change the needle clip??

any info would be great

[05exrder]

ummm nebody? kinda new and was wonderin how to adjust jets so a got lil more power so it will run leaner

[FoxMxRiders]

maybe adjust the air screw ... or the needle... maybe your to rich check your sparkplug

[05exrder]

yeah i am runnin rich it backfires now and then and runs like a dog with the lid off i gotta move the needle

[quad2xtreme]

You need to rejet if you are going to run with the lid off and you install a free flowing air filter.