Am I too lean with air box lid modified?

[hondaex03]

I have a stock 400ex and I took the air box off and turned the rear and side latches down and put the lid on and latched the front down. Know there is about 1 to 2 inch gap in the rear. It sounds better and it seems to have a little bit more bottom end. Will it make it run too lean with stock jet?:confused:

[AtvMxRider]

yes

Originally posted by AtvMxRider
yes

[Bill Fuller]

Anymore air feed into the carb will cause a "lean"effect.Now the question is is it to much.Well that depends how it was jetted before the added air flow.The only way to truley know is to check the spark plug.I would reccommend starting with a new plug for best results.Chances are it is lean like stated above,how lean it is is the real question.Find out before your baby lets you know........the expensive way!!Also ask your self this question.......Is it worth the 1 horse power gain?

[Steven]

yes it will!

refix the lid until you get some jets to play with